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In our first issue we made a general statement of the policy to be followed. The reception to Volume 1 has given encouragement for continuing and extending that policy. For the benefit of new readers, it may be easiest to explain this in action more specifically by reference to the contents of this issue. Firstly an account of work at the Cawthron Institute is given. Although its name is well known, there are many people who are not aware of the scope of subjects being investigated there, and the outline by its director, Sir
Different aspects of field biological studies are presented in the two succeeding articles. The study of the conversion of rain forest to grassland is one of special significance in this country which is so dependent on grasslands for its economy. The method of approach to a problem of plant ecology by Mr. Levy may be new to students who have confined their attentions to the study of “unmodified” associations. They will find that the inclusion of man's activities as a major modifying and controlling agency, gives some very interesting data and comparisons which closely link agriculaure with the study of the plant successions in vegetation unmodified by man. The account of a zoological field problem by Mr. Allen is of particular interest, as the popular interest of an animal usually increases as its numbers decline. In the essay on the grayling, a discussion of the possible reasons for the spectacular decline in numbers of this once abundant fish, will provide material for consideration by all interested in the problems of declining populations.
As in previous issues, keys for the identification of an animal and a plant group have ben given. The need for these in this country where so much descriptive work on species is still required, is so obvious that it does not require elaboration.
To some of our readers the contents of “Tuatara” may seem to be rather solid fare for a journal which is aiming to present general accounts of biological work. We feel, however, that it is better to retain the details necessary to support general statements, and readers may then be able to draw further conclusions from their own interpretations of the facts. In particular, it is hoped that teachers may find the contents in a form which can be readily used and expanded for class teaching.
The Cawthron Institute owes its origin to the munificence of Thomas Cawthron, who left practically the whole of his fortune, valued at $250,000, for the establishment and conduct of a scientific institute and museum.
The original trustees, appointed under the will of Thomas Cawthron, decided, on the recommendation of a Scientific Advisory Committee, that the major activity of the Institute should be research in the interests of New Zealand agriculture with reference to problems of both farmers and orchardists. The proposals of the Trustees were approved by the Supreme Court and early in 1920 the nucleus staff under the Directorship of Professor (now Sir Thomas) Easterfield was appointed and work was commenced.
Three main departments of scientific research were established in 1920 and these were maintained with but little change until the close of 1941 when a Biochemical Department was formed to handle more effectively plant and animal nutritional problems. The principal work of the four scientific departments is connected with (a) soil and general agricultural problems; (b) plant chemistry and mineral deficiency problems of stock; (c) insect problems of farm, orchard, and timber, and the biological control of noxious weeds; (d) fungus disease problems of fruit, hops, tobacco, and market garden crops. A technical museum, having special reference to the primary industries of Nelson and the natural history section of museum work, forms an integral part of the Institute and provides suitable facilities for the presentation of the work of the research departments to the general public.
Since the inception of the Institute seven additional bequests of a total value of some $50,000 have been received. In addition, the work of the Institute has been assisted from time to time by grants from the Empire Marketing Board, local bodies, and the primary producers of New Zealand. In recent years the Minister of Scientific and Industrial Research has given increased financial assistance for soil, mineral deficiency, tobacco, fruit, and entomological investigations of the Institute.
In several branches of research work, the staff of the Cawthron Institute collaborate with officers of the Department of Scientific and Industrial research. Entomological, tobacco and hop research, at Nelson, are conducted on a co-operative basis, both Cawthron and Government officers sharing in the research programme.
The Nelson district in which the Cawthron Institute is located has a climate which favours horticulture, and it is in this branch of agriculture that very marked development has taken place in recent years. The whole of the tobacco and hop industries of New Zealand are located in the Nelson district. In addition, Nelson has a very important section of the apple industry together with considerable acreages of small fruits, tomates, and market garden crops.
Arable farming, dairying, and sheep farming are all represented in the agriculture of Nelson, and at different times problems connected with these branches of agriculture in addition to horticultural crops have been investigated by the Institute.
One of the interesting features of the Nelson district is its diverse geology. Ultra-basic rocks of serpentine, basic rocks of melaphyre,
Although the work of the Cawthron Institute is not confined to the Nelson district, a great deal of its work is associated with the soils and special crops of Nelson. The work of the entomological department at the Cawthron Institute, however, has a more general application to agriculture outside the Nelson district in that the parasitic control of insect pests and the biological control of weeds, as a rule, apply in equal measure to agriculture throughout the whole of New Zealand.
In several aspects of both soil and insect research the Cawthron Institute has gained special distinction for the initiation and development of work of major importance to New Zealand agriculture. This is particularly true in connexion with the work carried out by the Institute in soil surveys, trace element deficiency, the parasitic control of insect pests, and the biological control of noxious weeds.
One of the important investigations commenced in the inaugural year of the Cawthron Institute was a reconnaissance soil survey of Waimea County, Nelson. This survey constituted the first systematic soil survey conducted in New Zealand which gave due recognition to the important part placed by both geological origin and texture in soil properties. Although modern methods of soil classification have necessarily entailed a revision of the soil groups identified in these early surveys, the units set out on the soil maps have required little alteration and have proved invaluable in the conduct of investigations relating to animal health, plant nutrition, and the manuring of crops.
Among the soils of the Waimea County which have proved of special interest to Nelson, and indeed to the whole of New Zealand, may be mentioned Moutere loams and Kaiteriteri loams. The Moutere soils have furnished spectacular deficiencies of lime, phosphate, nitrogen, potash, boron, and magnesium, several of which have seriously limited both yield and quality of crops—particularly of apples grown on these soils.
The Kaiteriteri group, derived from granite, has proved of no less interest in view of its association with marked deficiencies of cobalt, boron, and magnesium. In no part of New Zealand are the
The success achieved by the Institute in soil survey work in Nelson led to the establishment of a Soil Survey Division by the Department of Scientific and Industrial Research and the initiation of a reconnaissance survey of the volcanic ash soils of the central North Island territory of New Zealand. The Cawthron Institute was intimately associated with this and other surveys which were carried out in Taranaki, the Waikato, North Auckland, Hawke's Bay, and other parts of New Zealand. The reconnaissance survey of the volcanic ash soils proved of very great value as some of the soils were associated with stock ailment. When, as a result of other investigations, the cause of “bushsickness” was identified as cobalt deficiency, the survey of the volcanic ash soils made possible the immediate application of this discovery to practically the whole of the affected country in the North Island.
In more recent years soil survey work at the Institute has been concentrated on the detailed mapping of the alluvial soils of Nelson for the expansion of the tobacco industry. The results of the survey show that the Waimea County has some 10,000 acres of soil texturally suitable for the culture of flue-zured tobacco. Tobacco soil maps prepared from the soil examinations are proving of great value in the sound expansion of the tobacco industry.
The Cawthron Institute has played an important part in the identification of trace element deficiency affecting both animals and plants in different parts of New Zealand. The investigations of the Institute have comprised studies of cobalt deficiency on the granite soils of Nelson Province and on the loess soils of Southland; boron deficiency on two soil types in the Nelson district and on several soils in Central Otago, and magnesium deficiency of apples and tobacco on the granite and Moutere Hills soils of Nelson.
In regard to cobalt deficiency, studies of “bush-sickness” in sheep on the granite soils of Glenhope were commenced in 1928, and of lamb ailment in Southland in 1934. Evidence was slowly accumulated which ruled out a theory of iron deficiency as the cause of these stock ailments and suggested another element which was contained in certain iron ores and soil “licks” which had proved beneficial in the treatment of stock ailment.
Aided by the announcement from Australia that cobalt was an element of nutritional importance to stock, chemists at the Institute quickly showed that cobalt overcame stock ailments at Glenhope and Southland, and that there was an actual deficiency of cobalt in the soils, pastures, and organs of affected animals. The work carried out
As a result of the investigations carried out by the Department of Agriculture in the North Island and by the Cawthron Institute in the South Island, it can be said that cobalt deficiency on New Zealand has been overcome; the production of fat lambs and successful dairying has become possible over hundreds of thousands of acres which were formerly seriously affected by stock ailment or under suspicion.
Similar work has been carried out by the Institute in regard to the incidence of boron deficiency in apples, apricots, plums, and grapes on certain fruit soils in Nelson and Central Otago. Surveys of the boron content of soils and fruit have been carried out in all fruitgrowing districts of New Zealand and methods for overcoming boron deficiency have been studied. The investigations have shown that boron deficiency in fruit trees can be controlled by the use of half a pound of borax per tree or by the use of borax sprays at 0.1 per cent. strength. One of the interesting features of the experiments on apples was the adverse effect on keeping quality when borax was used in excessive amount.
More recently, studies of fruit trees in the Nelson district have shown the presence of magnesium deficiency on the Moutere Hills type of soil. Premature defoliation of trees had been noticed in certain apple manurial experiments of the Institute. Injection of different elements into the limbs of affected trees showed that magnesium salts were highly beneficial in controlling defoliation. Analyses of the leaves of affected trees showed a high deficiency of magnesium. The identification of magnesium deficiency in apples under commercial conditions of culture was of considerable interest. The Nelson work paralleled similar investigations carried out by Long Ashton workers and suggested the possibility of a fairly common occurrence of magnesium deficiency in horticultural crops on soils naturally low in bases, particularly where excessive amounts of potassic manures have been used. An interesting feature of the Nelson experiments on the control of magnesium deficiency in apples trees has been the success achieved with ground dolomite in restoring affected trees. This magnesium compound used at the rate of twelve pounds per tree has given more permanent benefit than the use of the corresponding quantity of magnesium sulphate.
Orchardists in New Zealand will always remember the spectacular success achieved by the Cawthron Institute through the introduction of Aphelinus mali parasite for the control of woolly aphis which, for
The parasite, obtained through Dr. Howard, United States of America, established freely in New Zealand and very quickly brought about a great reduction in woolly aphis, thereby saving many thousands of pounds in the cost of oil sprays.
Similar work has been carried out by the Institute in the introduction of the parasite, Habrclepis dalmani, for the control of Golden Oak Scale. Liberations of the parasite were made at Nelson, Christchurch, and New Plymouth. In every case the parasite was an outstanding success and gave an effective control of Golden Oak Scale.
A more recent introduction by the entomologists at the Institute has been that of Rhyssa persuasoria, for the control of the horntail borer which attacks pine plantations. The parasite has been liberated at several centres in the South Island of New Zealand and has multiplied rapidly. There is every indication that the parasite will prove valuable in the control of the horntail borer.
Although several insects have been introduced with a view to the control of noxious weeds in New Zealand, success has been somewhat limited. The Cinnabar moth and the ragwort seed fly were both introduced for the control of ragwort but so far have not been successful under field conditions in the control of this weed.
The Chilean saw-fly was likewise introduced in an attempt to control piri-piri, but although quite effective under laboratory conditions, this insect, so far, has not been successful under field conditions.
The gorse seed weevil, Apion ulicis, however, has established freely at all points where liberations have been made. Examinations of gorse pods show that the weevil is exerting a marked effect on gorse seed production and should eventually be an important factor in controlling the spread of the plant.
The recent introduction of the European beetle, Chrysolina hypersizi, for the control of St. John's Wort appears to be an outstanding success and is proving very effective in the control of this noxious weed in the Awatere Valley, Marlborough.
The establishment of the Entomology Division of the Department of Scientific and Industrial Research at the Cawthron Institute under the direction of Dr. D. Miller, Chief Entomologist to the Institute, has greatly strengthened entomological research at the Institute. The work carried out by the Government entomologists on the parasitic control of the White Butterfly and the Diamond-back Moth has been very successful and has resul ed in immense savings to farmers throughout New Zealand.
The horticultural crops of Nelson provide great scope for Cawthron mycologists. Their services have been in constant demand by orchardists, tobacco growers, and market gardeners, for the identification of diseases and for advice concerning their control.
Outstanding work has been done by the mycologists in the study of “Black-spot” of apples, “Brown-rot” of stone fruit, diseases of small fruits and tomatoes. In recent years very detailed studies have been made of tobacco mosaic and the factors which operate in its dissemination in the tobacco gardens. The importance of the seedling bed stage in mosaic transmission has been established and the necessity for the greatest care in handling plants to avoid infection has been stressed. Several tobacco diseases, new to the Nelson district, have been identified by the mycologists. Among these may be mentioned “Angular leaf spot,” “Verticillium Wilt” and “Black Root-rot.” The early identification of diseases and the application of suitable control measures have been of great importance in the successful development of horticulture in the Nelson district.
In this brief review of the work of the Institute it has been possible to describe only the more important activities of the Intitute. During the twenty-nine years of work at Nelson a great variety of work has been successfully handled and no less than 470 scientific papers have been published by members of the staff.
The success of the Institute has not depended solely on the results achieved by research. Of almost equal importance has been the great influence exerted by the Institute on farmers and citizens throughout New Zealand, in creating an appreciation of the value of scientific research.
The editorial committee has much pleasure in acknowledging the financial assistance given by the Wellington branch of the federation of University Women for the publication of the plate accompanying Dr. Allan's article. Assistance in the cost of printing this number of “Tuatara” was given from the Publications Fund of Victoria University College.
Owing to the greatly increased demand for the Journal three numbers will be published in 1949 in March, June and September. The subscription rate is 3/3 posted. Thank you for your support of the Journal. We regret that copies of Vol. I Nos. 1 and 2 are no longer available.
This resource is not yet available, pending copyright clearance.
Crustaceous lichens are abundant in New Zealand both in species and individuals. They occur on rocks from sea-level to the upper limits of plant life. They are also plentiful on bark and soil, while one family is confined to the surface of leaves. Opinions differ greatly concerning the limits of families, genera and species, and for detailed knowledge intensive microscopic work is required. It is not impossible, however, to gain a good general knowledge of families and many genera by fairly simple observational methods. For ecological purposes this general knowledge is not to be despised as hitherto lichens have been sorely neglected in studies of vegetation. A difficulty is that there remain probably many hundreds of species yet to be collected and identified. Several overseas specialists are anxious to obtain specimens from New Zealand of their particular groups and a student desiring to make any special study would do well to get into touch with one of these workers. The numbers of the figures attached to this note follow on from those of the previous note in “Tuatara,” Vol. 1, No. 3.
STRIGULACEAE.—Two genera of this family are known in New Zealand on the leaves of tawa, titoki, ramarama, Asplenium and a few other trees and shrubs. Strigula has a more or less orbicular yellowish thallus, and Phylloporina a more irregular greyish thallus.
VERRUCARIACEAE.—Verrucaria is the genus most commonly met with in New Zealand. The species are most prevalent on coastal rocks, the thin dark thallus closely investing the rock-surface.
PYRENULACEAE.—Mostly bark-inhabiting species with several genera represented here. A species of Arthopyrenia forms tiny dark spots on sessile barnacles. There are several species of Pyrenula not easily distinguished in the field.
CALICIACEAE.—The stalked fruits of Calicium look like minute pins stuck on the thallus. The family has not been much studied in New Zealand.
CYPHELIACEAE.—A species of Cyphelium with a greyish thallus and uniseptate brown spores occurs on rock in tussock-grassland.
ARTHONIACEAE.—A few bark-inhabiting species of Arthothelium with muriform spores have been recorded. A. vermiferum forms small greyish flecks on the leaves of Metrosideros colensoi and other species.
GRAPHIDACEAE.—The family is widely distributed here, but has been little studied. The genera found are keyed.
LECIDEACEAE.—A very large family with many genera and a multitude of species. Zahlbruckner lists over sixty species of Lecidea for New Zealand, others have been recorded and described, and probably many more await discovery.
Catillaria is well represented, but the species are difficult to distinguish by simple characters. A few species of Megalospora have been recorded; M. marginiflexa is widely distributed on the bark of trees. Bacidia occurs on rock and bark, both coastally and inland. One species has been recorded from leaves of podocarps.
Toninia belongs to this family, but has a corticate, warted squamulose thallus. One species occurs on limestone. Lopadium—The several species of this genus recorded for New Zealand occur on leaves. L. coerulescens has a wide range of hosts, including Asplenium. Rhizocarpon has several species, of which R. geographicum with a greenishyellow thallus is widespread on rocks. It is striking on account of the more or less “map-like” arrangement on the rock surface.
THELOTREMACEAE.—We have a few species of Thelotrema with muriform spores. Surrounding the proper margin of the apothecium is an overarching thalline margin.
LECANACTIDACEAE.—The species of this family, related to the Graphidaceae, have a thin thallus. The proper margin of Lecanactis is quite prominent.
PERTUSARIACEAE.—The apothecia are immersed in thalline warts and the spores are simple. In Perforaria the apothecium has a small pore-like opening; P. cucurbitula is widely distributed and occurs on bark, rock, dead vegetation, moss and soil. We have about forty species of Pertusaria, in which the apothecia have a wide opening.
BUELLIACEAE.—Members of the family superficially resemble Lecideaceae, but the spores are brown and two-celled. We have a number of species of Buellia, mainly on rock. We have also several species of Rinodina, distinguished by the thalline margin to the apothecium.
LECANORACEAE.—A large family, well represented in New Zealand.
CALOPLACACEAE.—Two genera are represented: Blastenia, the apothecia lacking a thalline margin; Caloplaca, the apothecia with a distinct thalline margin. The former is poorly represented, but we have some twenty species of Caloplaca, the small apothecia often light yellow or red.
Legends To Figures
The drawings have again been kindly contributed by Miss N. Adams, Botanical Artist to the Botany Division, Department of Scientific and Industrial Research.
40. Haematomma puniceum.
41. Ochrolechia parella.
42. Lecanora dennanensis.
43. Lecanora pachypholis.
44. Megalospora marginiflexa.
45. Graphis tenella.
46. Thelotrema lepadinum.
47. Lecidea dunedina.
In a land where there were no native mammals, fish were a very important source of food to the Maori before the coming of the white man, and the Maori became very skilled in their capture, both in the sea and in the fresh-water lakes and rivers. Although some fish, particularly the larger species, were caught with hooks and lines, the Maori depended to a large extent on the use of nets and traps of which he developed many ingenious forms. Among the fish, then abundant, which he caught in the rivers in this way was one generally called the Upokororo, although like most animals known to the Maori it had a number of other names, either peculiar to certain tribes or denoting particular phases in its life history. This fish entered the rivers at certain seasons of the year in large shoals, and was found in many parts of the country. One of the most usual ways of taking it was by setting basket-work traps in the rapids with their mouths upstream and with two walls of boulders arranged in a V to divert the current and any fish moving downstream into the trap which was fixed at the apex of the V. When the trap was set it was sometimes left overnight, so that fish moving out on to the rapids from the pools to feed were swept into it and caught. On other occasions the fish were driven out of the pools upstream by men armed with long poles, and, fleeing downstream with the current, were carried headlong into the trap. That other and possibly more original methods were sometimes used is suggested by an early writer on New Zealand who says of the grayling: “It bites at the hairs of the legs and is thus caught by the natives going into the water.” Unfortunately, it is not quite clear whether the fish took firm hold and the natives then walked out towing the fish!
When the white man arrived he found the graylng both widespread and abundant, although it was some time before it attracted the notice of scientists. Apparently, however, it received the English name of “grayling” at an early date, presumably on account of its superficial resemblance to the European species of that name in its slender shape, silvery scales and the possession of an adipose fin, although it lacked the very large dorsal fin which is such a characteristic feature ot the true graylings. In 1869 some specimens were sent to Frank Buckland, who passed them on to Dr. Gunther at the British Museum. In the following year Gunther described them, naming the species Prototroctes oxyrhynchus, and referring it to the family Haplochitonidae; a family which is related to the northern trouts and whitefish but which has a southern hemisphere distribution.
At this time the species was still abundant and Hector in 1871 says that it was “found in most of the streams of the colony,” and goes on to speak of the “immense shoals” ascending the Hutt River in January. Apparently, however, signs of decreasing numbers were evident soon afterwards, and in 1878 Rutland, who studied the species in the Nelson and Marlborough district, notes that in the Maitai River it has “become very scarce during the past three years.” This disappearance continued rapidly and by the 1920′s the species was known to exist only in some streams in the East Cape, Wairarapa and Otaki districts in the North Island, and on the West Coast of the South Island, and even in these areas it had so decreased in numbers that instead of being present in large and conspicuous shoals, the few specimens occasionally taken were considered so unusual as to be worthy of record. In the last twenty-five years there have been no further recorded occurrences which I have been able to trace, although I was told by a reliable observer in 1939 that he had seen them two or three years earlier in a river in South Westland.
Drawing by
Thus it seems clear that this fish, which was apparently abundant throughout many parts of New Zealand when the Pakeha first arrived, and which remained abundant until at least 1870, declined rapidly in numbers, until fifty years later it was confined to a few isolated parts of the country, and has since continued to decline, so that no known stocks now remain. The accompanying map shows the districts from which it has been reliably recorded; the shaded areas being the approximate drainage basins of the rivers in which it is known to have occurred, while the black circles represent localities from which the species has been reported since 1920. The appearance of the map together with a number of less precise reports suggest that the distribution on the west coasts of both islands was probably much more continuous than is indicated, but it seems likely that it may have been relatively scarce on the eastern coasts. There appears to be a fairly close degree of correspondence between the known distribution of the grayling and the areas which were originally covered in forest.
The causes of this disappearance form an interesting subject for speculation, but unfortunately at this late date it cannot be very much more. There seem to be three most likely causes to consider if we assume, as appears justifiable, that it has resulted from some activity of the white settlers. These are—that man has taken sufficient direct toll of the species to cause its disappearance: that he has, by some means such as the clearing of bush from the water-sheds, so altered the habitat that the fish can no longer survive: or that the introduction of the trout has somehow destroyed the grayling. Of these, the first seems most unlikely; there is little evidence of the grayling being subjected to fishing for the market except in a few cases, and with the coming of the trout few anglers would be interested in it, although earlier on it was fished for in some places. Also, it seems to have disappeared even from streams in sparsely settled districts where any intensive fishing would be most improbable. The widespread clearing of the bush and other agricultural practices have undoubtedly seriously affected many rivers, generally causing an increase in the extent of the shifting shingle of the beds and more violent floods and droughts. These factors are generally adverse to most species of fish and could conceivably have been particularly adverse to the grayling. However, the species seems to have disappeared not only from waters affected in this way but also from others, particularly in Westland, where the bush covering of the water-shed has not been touched.
It seems then that neither of the above possibilities is likely to have been the cause of the disappearance of the grayling, and serious consideration must be given to the third possibility—that the grayling has been unable to survive in the presence of trout. There is some evidence that supports this possibility. In one of the few cases where a date can be put to the decline of the grayling—the Maitai River in Nelson—we find that it began to be scarce about 1874, and trout were first introduced into this river in 1870 and were apparently successfully established. It is also noticeable that some of the waters in which grayling are known to have been present at a relatively late date, the Waiapu River near East Cape, the Turanganui near Featherston, and the Wahapo River in Westland, are all waters where trout are present only in small numbers. On the other hand, grayling are said to have disappeared from the Waikato about 1874 (the same year that saw the beginning of the decline in the Maitai) although trout were not established there until at least ten years later. There are also many waters in New Zealand which do not contain trout, and from all of these the grayling is now absent. This absence may of course be due to the unsuitability of these streams to grayling as well as trout, but if they were ever present the introduction of trout cannot have caused the disappearance.
Thus none of the suggested explanations seems to cover the facts fully, and the true cause of the disappearance of the grayling must remain a mystery. The apparently simultaneous disappearance in waters as diverse as the Maitai and the Waikato tempts one to consider an epidemic as a possible cause, but there is no other evidence supporting this and on general grounds it seems most unlikely. The whole position is made still more obscure by the lack of reliable information regarding the life history of the fish. It apparently ascended the rivers in large shoals, composed of fish between 5 and 12 inches in length. These shoals after their ascent rested in the bottoms of the deep pools by day and were believed to come out on to the rapids, to feed upon filamentous algae and other growths encrusting the stones, at night. It is said that their presence could be detected by their teeth-marks on the stones when feeding in this way. After remaining in the rivers for some time they disappeared, although no definite downward migration seems to have been observed. The ascending fish were heavy with spawn, but no observation of their spawning habits has been recorded, nor has the presence of the young stages. It seems most likely that the ascending fish were coming up from the sea, but even this is not definitely established. There are some discrepancies between the various accounts as to the time of year in which it was in the rivers, but most of them seem to accord with the following outline. The movement into the rivers began about early or mid-summer, and from then until about March or later the fish were slowly moving upstream. In late autumn and early winter they were in the upper reaches of the rivers and if this was a spawning migration spawning probably actually took place at this time. In late winter and early spring they disappeared, perhaps returning to the sea. When first entering the rivers they were silvery in colour, slightly brown on the back, but appear to have gradually become darker, being finally rich brown on the back and yellow beneath.
The little that is known of its life history thus gives no clue to the causes of its disappearance, but there still remains the possibility that the study of a surviving stock, if one exists, would not only reveal the life history of this interesting species, but also explain why it vanished under the impact of European civilization. At present, however, we do not even know whether it is indeed extinct, or whether, like the now-famous takahe, it still survives in some unfrequented spots.
K. R. ALLEN, Fisheries Laboratory, Wingfield Street, Wellington.
The native Grayling: as explained elsewhere in this issue the history and biology of this fish is somewhat mysterious, and it is not even known whether it still exists. Any records of its occurrence during the past twenty years, or specimens or notes of locality, number, size and season would be very welcome to Mr. Allen. The only fish with which it may be confused are the trout and salmon and the native “smelt” or “silvery.” It may be distinguished from the former by the generally smaller size (5-12′) and absence of spots, and from the latter by the larger size (the smelt is generally 2-5”), absence of a bluish stripe along the flanks and relatively forward position of the first dorsal fin which in the smelt is approximately above the vent. In no other fish is there a second dorsal fin reduced to a fatty protruberance.
Metamorphosis—alteration, often of a profound nature—occurs in the life-cycle of all but directly developing amphibians. The New Zealand frog Liopelma has a direct development, but most other frogs, and the newts and salamanders, undergo more or less metamorphosis in the transition from larval to adult forms. External change is obvious to anyone who has watched, even casually, a developing frog: the development of external gills and their later loss; growth of limbs; absorption of the tail; the straightening and shortening of the tightly coiled, larval intestine, and the growth of the adult jaws follow each other in orderly sequence. Among newts and salamanders, fundamental changes, although not so apparent as in the frogs, nevertheless do occur—external gills and tail fins are reduced and absorbed and adult colour markings are assumed.
There are, however, internal changes at metamorphosis no less profound, but less observed and certainly less understood, than those occurring externally. One of these changes, probably unrecorded until Major S. S. Flower in 1927 noted its occurrence in the European Spotted Salamander, is a complete loss of memory which coincides with the metamorphosis. Such loss of memory indicates change in the nervous system of this salamander at metamorphosis. Major Flower kept three newly-born salamanders in separate jars. By giving individual attention, all three soon became tame enough to show no fear when approached, would take proffered food, and after some weeks, would even call attention to themselves when hungry by active movements and sending out bubbles. As metamorphosis approached, appetites increased, and the animals would freely swim to his hand and take earthworms.
Metamorphosis is complete, Flower says, when the larval gills disappear. This occurred on different days for each of the three salamanders. Although the environmental conditions were quite unchanged, all memory of their human attendant was lost in each case on the day of metamorphosis. Close approach to the jars frightened the animals; they tried to avoid capture by the hand and struggled wildly if picked up, they would not feed. A process of re-taming, taking several weeks, had to be undertaken, as though they were freshly-caught wild animals.
Flower's work points to an interesting and little known aspect of the metamorphosis of amphibians, an aspect that might well repay further study.
The New Zealand crabs have had a stormy systematic history. Even today there is no complete convenient account available describing these common and interesting animals which are such an important element in our marine fauna. This guide is not a final statement of the systematics of these animals. It is only a step in bringing this part of this fauna within the reach of students and cannot as yet be carried to completion because much literature is unavailable. It has been developed from my personal needs and is presented here as an aid and stimulus to the researches which are yet to be undertaken. I will be very grateful for any corrections, alterations or additions which can be suggested. Many species of our crabs are poorly known, some only from a brief account of the one original specimen and the status of others, even of common species (e.g. Ozius truncatus) is still in doubt. Species are included in the guide which are doubtfully part of our fauna. These species are bracketed and noted here to enable their recognition if actually present.
This is a guide to our crabs of the families Portunidae, Cancridae, Xanthidae, Grapsidae, Ocypodidae and Pinnotheridae, which are Brachrhyncha—crabs in the ordinary sense, lacking a rostrum, having a round to squarish body, the mouth located in a square to oblong area (the mouth-field), covered by the mouth-parts of which the third maxillipeds are the external elements. These Brachyrhyncha contrast with the spider-crabs and masking-crabs which also have an oblong mouth-field, but in these the carapace is commonly triangular in outline with the apex anterior so that these crabs are grouped as the Oxyrhyncha. Because of the common oblong form of the mouth-field, crabs and spider-crabs are grouped together as Brachygnatha. In this respect they contrast with another common group of crabs, the Oxystomata, in which are included the ball-shaped crabs, the box-crabs, and the flat-back crabs—varying much in shape but having in common a narrow, elongate and rather triangular mouth-field.
Several portunid crabs not listed in the key have been recorded from New Zealand. In particular species having 9 antero-lateral spines should be watched for and reported if found. There appear to be only the two species of cancrid crab; the xanthid crab fauna is richer but very inadequately known and much further research is required. I have handled two additional distinct species, neither identifiable with the species listed in the key. The grapsid and ocypodid crabs are reasonably in order but the pinnotherid crabs are in need of extensive
P. pisum, a European species has been identified in New Zealand material by at least two specialists, one of whom considered our dwarf Portunus as the northern hemisphere Portunus corrugatus. Local students may find the opportunity for important work in the description and revision of Xanthidae and Pinnotheridae.
The key is drawn from many sources, but its content is largely determined by Chilton and Bennett's review of the Brachyura (Trans. N.Z. Inst., v. 59, 1928) which clears the fauna of some species, establishes the nomenclature for others, and gives a ready entry into the literature on this subject. Rathbun's monographs (U.S. Nat. Mus., Bulls. 97, 129, 152, 166) are invaluable as a reference and guide in many problems, and will be found most useful for further detail required in advanced studies.
The figures are restricted to an outline of the carapace and it must be noted that to enable presentation of all these species in two plates, the figures are drawn to much the same size. The figures are not drawn to scale which would have been well-nigh impossible for this guide since the species illustrated range in width from one half inch to four inches and a half. An indication of the width of each species is given in the key. For much the same reason, the ornamentation of the surface of the carapace is commonly omitted. The figures are useful only in conjunction with the key. Each illustration shows the fronto-orbital width (between the lateral orbital spines, marked by the outer pair of arrows), the contour of the front (between the orbits, between the medial pair of arrows), and the antero-lateral and postero-lateral margins of the right side. Excepting where noted in the key, the spines at the orbital angles are included in the count of the antero-lateral spines, and frontal spines respectively.
The keys are set out as far as possible on a natural systematic basis, so that confusion between the species included and others is unlikely. The features selected are generally readily observable, but difficulty will be found in the case of the Xanthidae. The important ridges which are mentioned in 1 (4) can only be seen by turning the mouth-parts well down. If present, the ridges may be low, rounded and not very conspicuous; if absent, the plate anterior to the mouth will be quite smooth, as for example in Ovalipes. The reference numbers, e.g., Key to Families, 1(6), are alternatives. Where there is not agreement with 1, then refer to 6. Where the agreement is with 6, then proceed to 7, etc. This type of key is advantageous in that the summary of the features fitting the specimen give the essential points in the generic and familial definitions. Also, the method permits a ready return through the key when errors have been made, or when the review of the features dealt with is desired.