Otago Institute.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 42, 1909, Unnumbered Page

Otago Institute. First Meeting: 11th May, 1909. Professor Park, President, in the chair. The following is a summary of the presidential address by Professor Park, entitled “The Glaciation of Otago”:— The lecturer stated that, in accordance with instructions received, he made, in three successive years, a geological survey of Central Otago, commencing at the Maniototo Plain and working westward to Wakatipu. He discovered that Central Otago was occupied by a remarkable group of block mountains, which were table-topped, and bounded by powerful dislocations. Practically all the mountains in Central Otago were so distinguished—the Hawkdun, Dunstan, Pisa, Carrick, Garvie, Old Man, and Umbrella Ranges being typical examples. The origin of these mountains was peculiar, and, in themselves, they belonged to a unique and distinctive type, without a parallel elsewhere in the Southern Hemisphere. But before considering the origin of these block mountains they might first look at the ordinary type of mountains, with which every one was familiar, as, for example, the Alps of New Zealand or of Europe, or the American Sierra Nevada, or the South American Andes, the summits of which were irregular and deeply serrated, and often so narrow as to form a mere razorback. Examination of their structure showed that the rocks of which they were composed were arranged in folds, often very complex. Geologists the world over had offered explanations of the peculiar formation of block mountains, but only two of these latter were worth considering. Professor Suess, of Vienna, conceived a great plateau or plain, which he considered had been broken up by great cracks or fissures. Certain sections had, by a subsidence, been left at a much higher level than others, with the result that they now had, with all sharp corners worn off, the table-topped mountains and intervening basins. Professor Davis, of Harvard, on the other hand, postulated a plain at or about sea-level, cracked by great dislocation, and subjected to unequal uplift. These were the theories that had been formed regarding the very remarkable mountains of Central Otago, mountains that distinguished New Zealand, and which would in future years attract many scientists to the Dominion. The whole of Central Otago was occupied by these flat-topped mountains, on which a person might, in some cases, conveniently ride for over a hundred miles. The lecturer next directed attention to the glaciation of New Zealand. During the progress of his geological work he had been fortunate enough to obtain evidence to show that New Zealand at one time had a glacial period similar to that of the Northern Hemisphere. He had been able to prove that Otago and the greater part of the South Island were covered with a continuous ice-sheet—probably an extension of the south polar ice. In the Wakatipu basin the ice in thickness exceeded 7,400 ft., this immense glacier, it would appear, being fed by three streams. It had flowed over the top of Mount Nicholas, which had been cut into the shape of an immense dome, beautifully rounded and smoothed, and flanked by beautiful U-shaped valleys. Every one had heard of the glacial period of the Northern Hemisphere, often spoken of as the Great Ice Age, that took place in the Pleistocene—the period which preceded that in which we live—the geological yesterday. The north polar ice invaded North Europe, northern North America, and North Asia, and steadily advanced until it reached latitude 50O, carrying with it destruction and desolation. The forests were overwhelmed and completely obliterated, while the animals and men inhabiting these continental areas retreated southwards before the terrible blighting wall of ice. But animals in the insular areas, being unable to escape, sought refuge in caves and holes in the earth, and there miserably perished. In Western Europe the ice-wall covered Norway and Sweden, the whole of Scotland, and the greater part of England. In Scotland the maximum thickness was 5,000 ft., and in Central Europe 7,000 ft. In course of time this ice-sheet retreated, and left the features of the land curiously altered. The mountains, ridges, and spurs were ground down and truncated, the valleys

were broadened, and the lakes deepened. Hard rocks were smoothed, polished, and striated by the sheer weight of the moving mass of ice; and everywhere the land-surfaces presented rounded, mammillated, gently undulating contours—all the irregularities and asperities of the country having been worn away by the movements of the enormous mass of ice. Much of the land was covered with a sheet of boulder-clay, mainly composed of transported rocks, and perched blocks, some of them of enormous size, were left here and there on the ice-worn ridges. The lecturer said he would be able to show them that the evidences of prolonged and intense glaciation were as conspicuous in New Zealand as they were in Europe. He would show them that the slopes of the mountains, up to a height of 6,500 ft., were ice-shorn into what were, without doubt, the most marvellous tiers of ice-steps or benches in existence. As evidence of the presence in the Pleistocene period of that great ice-cap in Central Otago, he could show them ice-cut platforms, glacial lakes, eskars, moraines, perched blocks, erratics, striated and polished rocks and boulders—in fact, all the phenomena of the glaciation of the Northern Hemisphere. That conditions such as these must have attended the presence of this ice-cap had obtained in New Zealand in comparatively recent times was a weird and mysterious thing—something, indeed, almost incredible; yet the evidence that this mass of ice had been all over Central Otago was so fresh that they might easily imagine it had retreated only yesterday. There had been two phases of the Great Ice Age. The first was that in which there had been a continuous ice-sheet extending from sea to sea, when 7,400 ft. of solid ice stood in the Wakatipu basin. In the second phase the valleys were filled with enormous glaciers. The extent of these ice-rivers was surprising. There had been one that extended westward from Alexandra a distance of 140 miles—which meant that it was longer than that great glacier traversed by Lieutenant Shackleton in Antarctica, which was believed to be some 130 miles in length. The Wakatipu glacier had split into a number of streams. One passed southward towards Kingston, and another formed the Kawarau glacier, which presently joined with the Shotover glacier. These were joined by the Arrow glacier, which was smaller, and, in consequence, twisted round and jammed up against the Crown Range, the slopes of which were wonderfully and beautifully scored. To the action of the Arrow glacier was due the formation of the Crown Terrace, which was excavated out of the solid rock. The pictures thrown on the screen showed many photographs of the rocks and mountains of Central Otago. One disclosed a huge boulder of greywacke lying in a country altogether foreign to it—in geological language, a perched erratic. It had been brought on the travelling ice-cap over lake, and mountain, and glen, from the Livingstone Range to its present resting-place. Another picture, which the lecturer described as the most remarkable of his collection, showed the rocky side of Mount Benmore cut into a series of almost regular rock-terraces. They were the most remarkable terraces or steps he knew of. There was nothing like them in Europe, and no one could doubt their glacial origin. Close to Arrow there is a perched erratic rock, measuring 24 ft. by 12 ft. by 10 ft., and weighing 240 tons. It is an enormous mass, and yet geology proves that it rode in a glacier all the way from the Livingstone Range. Indications point to its having been nearer the bottom than the top of the ice-river, for a portion of it is deeply striated, as if it had been dragged for many miles over a rocky surface. Other pictures showed a clay bank at Henley, proving that this was the moraine of a great glacier that had emptied itself into the sea comparatively close to Dunedin; and the Queenstown Domain, also an old moraine, and now covered with striated boulders belonging to far-distant parts of the mountains. Near Cromwell was the old Kawarau moraine, with its foreign and weirdly cut rocks. In fact, right over Central Otago were striated rocks in thousands, and erratic rocks in millions. Other pictures disclosed the secret of the formation of Moke Lake, near Moonlight. Two glaciers had been forced out of the Wakatipu basin, and had come by separate valleys down towards Moonlight. Truncating the ridge that separate them, they had come together, and their united crushing-power had torn out the “twin” hole now filled by Moke Lake. It was in a similar way, by lateral branches from the Wakatipu glacier, that Lake Dispute had been formed. The shape of the hills throughout Otago and Southland indisputably proved glaciation. There were the smooth contours and flowing outlines that necessarily followed the grinding process of a glacier. There were the ice-shorn mountain-tops, and the gentle upward plane torn by the ice as it was pressed upwards, and the place where, having reached the top, and the pressure behind removed, the glacier dropped suddenly down.

The lecturer considered that the Wakatipu Valley existed before the glacial period. The ice had, however, probably broadened and deepened it, at the same time rounding the contours of the overhanging mountains. Three powerful dislocations ran parallel with the arms of the lake. The greatest depth in the lake was 1,240 ft., which was 240 ft. below sea-level. It was, therefore, not possible that the action of water had dug out that enormous hole. The probability was that faults or dislocations had in part formed the lake-basin, for he thought it was not competent that ice could dig to such a depth. In view of all the circumstances, it was almost impossible to give a dogmatic opinion. Perhaps the simplest solution was to go to the Maoris, who explained the existence of the lake in an interesting way. One legend had it that a Maori wandered among the mountains with a wooden spade in his hand, and wherever he thought a lake should be, there he dug a lake. Another had it that a giant who lived in the mountains came to the coast and abducted a lovely brown maiden, and, taking her to Wakatipu, fastened her to a cabbage-tree. Her father, very wroth, offered the fair one in marriage to the first man brave enough to rescue her from the giant. One young man ventured to Wakatipu, released the maiden, and set fire to the fern, and the sleeping giant was overcome by the fire and smoke, and died. He kicked furiously in his death struggles, and thus tore out of the earth the hole that now holds Lake Wakatipu. Third Meeting: 6th July, 1909. Professor Park, President, in the chair. Professor C. Chilton delivered an address on “The Subantarctic Islands.” He exhibited a series of pictures illustrating the appearance of the land and the general character of the vegetation of the various islands set around the antarctic region—Macquarie, Marion, Kerguelen, South Shetlands, &c. The similarity of the fauna and flora was illustrated by pictures of the more striking allied species found on the different islands. This geographical distribution compelled one to believe that in former times there had been much more extensive land connections between these islands and the neighbouring continents, a conclusion held for some years by many naturalists, and now confirmed by the discoveries by recent polar expeditions of numerous additional similarities, and especially by the discovery of land around the Pole by Lieutenant Shackleton's expedition. Fourth Meeting: 10th August, 1909. Professor Park, President, in the chair. New Members.—Messrs. F. B. Morris (of Oamaru), E. R. Green, and T. M. Gillies. The President made some remarks on several books recently acquired for the library. He especially commented on the valuable and monumental work by Dr. Hocken, “A Bibliography of New Zealand Literature,” just issued by the Government Printer. Mr. G. M. Thomson stated that the forty-first volume of the Transactions had left his editorial hands a couple of months ago, and would shortly be issued to members direct from the Printing Office. The Second Part of the Proceedings was also due. The President announced that a special meeting of members would be held on the 24th August for the reading and discussion of papers by Dr. Marshall and himself on the subject of glaciation in the South Island, arising out of his presidential address.

Fifth Meeting: 14th September, 1909. Professor J. H. Scott, M.D., in the chair. Papers.—1. “Notes on some Rocks from Parapara, Bluff Hill, and Waikawa,” by J. Allan Thomson; communicated by George M. Thomson, F.L.S. The author describes in detail six specimens from Parapara, furnished by Dr. Bell, Director of the Geological Survey, the object being to test the rival theories of assimilation or absorption, as propounded by Levy and Lacroix, and of differentiation, supported by Rosenbusch. The investigation serves chiefly to draw attention to the question, as the phenomena observed admit of either interpretation. A through chemical examination of the rocks would be required to settle the problem. The rocks from the Bluff were collected along the shore on the south and west of Bluff Harbour. The relative ages of these different rocks—fine grained banded hornblende schists, and dark and light diorites—the mode of origin of the foliation, whether

arising during or after consolidation, the origin of the rock-variations and “basic secretions,” whether by pure differentiation or differentiation combined with absorption, are a few of the problems presented for solution. The last rock is an isolated beach-pebble picked up at Waikawa, and possesses interest as being a type not hitherto recorded in New Zealand. The other beach-pebbles consist mainly of microgranites derived from the Triassic conglomerates; but from its soft nature it is more probable that this rock has come from a neighbouring intrusion. It shows a rich mineralogical association, consisting of amphiboles, biotite, muscovite, clinozoisite, epidote, two varieties of chlorite, talc, magnetite, and pyrite, but hornblende is so abundant as to render the designation “lustre-mottled hornblende rock” applicable. 2. “On a Method of introducing the Decimal System in British Weights, Measures, and Volumes,” by Henry Skey. Weights.—The pound is the unit, placed in the middle of a symmetrical system or scale, and the numerical method of counting is proposed up to 10,000, and the division of the pound into 10,000 new grains called minis. Thus:— 10,000 minis = 1 pound. 10,000 pounds = 1 myriapound. Measures.—This deals with the advantages to be derived from employing a unit of 10 inches, making a new foot, or ped, for the centre of the system, counting its multiples up to 10,000, and the divisions of it into 10,000 parts called minipeds. Thus:— 10,000 minipeds = 1 ped. 10,000 peds = 1 myriaped. Volumes.—A new measure, which may be called a vol, is made the centre, it being the tenth part of a gallon, counting it up to 10,000; the vol itself being divided into 10,000 parts called minims, thus showing the advantages to be derived from dividing the pound weight into 10,000 minis, for the weights and volumes for water can be made identical throughout, and can thus check each other. Thus:— 10,000 minims = 1 vol. 10,000 vols = 1 myriavol. The weights, measures, and volumes are thus all shown to be connected and intercalculable. These papers form a continuation of a former paper on the currency. 3. “Some Notes on the Glaciation of Wakatipu Region,” by Professor James Park, F.G.S. This paper traversed Dr. Marshall's views as to the ancient glaciation of Otago. The author believed that the glacial epoch consists of two phases, the first being the period of maximum refrigeration, when the greater portion of the South Island was covered with an ice-sheet, and the second the period of valley-glaciation. He contended that the surface-features everywhere showed two generations of erosion—namely, the glacial, distinguished by smooth, flowing contours; and the fluviatile, impressed on the former, and often obliterating it. Domed hills, truncated spurs, and glacial shelves were to be seen in many places along the east coast of Otago; and added to these there was the Taieri moraine, over twenty miles long, three miles wide, with a thickness exceeding 1,000 ft. It was the greatest accumulation of morainic material in New Zealand, and, when considered in conjunction with the glacial surfaces, must be taken as conclusive proof that the Otago ice-sheet reached the present coast-line. The author contended that, judged by the criteria of glaciation formulated by Dr. Marshall, no ice-sheet ever crept over Scotland. No terminal moraine, for example, marked the southern limit of the ice-sheet in England. Chamberlain, Garwood, and others had shown that the differential movement of the layers of a glacier were due to thrust, disproving Dr. Marshall's contention that ice was incapable of producing thrust. The Hector mountains showed ice erosion up to 6,500 ft., and Ben More was terraced to nearly the summit, 6,000 ft. high. The author considered his estimate of 7,490 ft. thick a conservative one. Taking the mean gradient of the Greenland ice-sheet, the Wakatipu ice-sheet must have reached the east coast.

Sixth Meeting: 22nd September, 1909. Dr. Fulton in the chair. Papers.—1. “The Great Ice Age of New Zealand,” by Professor James Park. In this paper the author summarised the evidences of glaciation seen in the Wakatipu region, on the east coast of Otago between the Clutha and Waitaki, in Canterbury and Nelson. A detailed description was given of the Taieri moraine, and Kaikorai glacial deposits near Dunedin, and of the boulder-till covering the Hautapu Valley along the Main Trunk Railway in Wellington. He contended that Dr. Marshall was in error in saying that a boulder-clay was relatively thin because formed under the ice. In North America the tills are found 500 ft. thick, and m Germany 670 ft. thick, while a Permo-Carboniferous till found in South Australia is 1,500 ft. thick. Besides, tills are not uniform and continuous sheets, but notoriously irregular. The beautiful, smooth, flowing contours of Otago were the result of ice erosion, as stated by J. T. Thomson in 1875. South America was glaciated for 1,400 miles north of Cape Horn, up to latitude 37o S., and he thought the evidence conclusive that New Zealand had participated in the general glaciation of the Southern Hemisphere. Captain Hutton, in his glacial map of New Zealand, showed nearly half of the South Island covered with a continuous ice-sheet. The author believed there was now sufficient evidence to warrant the belief that the greater portion of the Island was glaciated. He thought the glacial period of New Zealand was due to elevation, which increased the area to continental dimensions, and linked it up with the outlying southern islands, at the same time diminishing the width of sea to the Antarctic. The New Zealand ice-sheet would radiate from the elevated centre of movement towards the sea, and would thus meet the advancing polar ice, which would, however, be kept off the New Zealand shores by the superior thrust of the land-ice. Mr. G. M. Thomson advanced several reasons from the botanical point of view against the theory that a glacial epoch prevailed in Pleistocene times in New Zealand, and that what now constituted the South Island (which, according to Professor Park, was only separated during that epoch) was then covered with an ice-sheet. (1) The flora of New Zealand contained, according to Cheeseman, 332 genera and 1,415 species of flowering-plants. Of this number 2 genera (Stilbocarpa and Pleurophyllum) and 45 species are peculiar to the Antarctic Islands (Macquarie, Campbell, Auckland, Antipodes Islands, and the Snares); while 26 genera and 452 species are found in the South Island and Stewart Island, but do not range into the North Island. These peculiar South Island forms included such aberrant types as Ranunculus Lyallii, the whipcord Veronicas, the vegetable sheep (Raoulia eximia and mammillaris), the remarkable woolly Haastias, and many other singular plants. They formed one of the most interesting collections to be found in any part of the world. He argued that the extraordinary diversity of form and type which prevailed among these genera and species required a very considerable period of time for its development, and that the differentiation probably dated from an era much antecedent to the Pleistocene. (2) One of the effects of recent glaciation in the Northern Hemisphere was to produce among the woody plants a deciduous type, such plants only, unless specially modified for the purpose, being able to resist the destructive effects of snow. Taking Britain as an example of an area glaciated within recent geological times, he found that of the 1,223 species of flowering plants in its existing flora, only 91 (or 7.4 per cent) were trees or shrubs. Of these, 26 (or 28.5 per cent) were evergreen, but these included all the small-leaved or hard-leaved species, such as Scotch fir, juniper, yew, heaths, gorse, &c., which were not injured by snow. The only soft-leaved evergreen in Britain was the ivy, which did not hurt with snow. All the other trees and shrubs, to the number of 65 (or 71.4 per cent of the whole), were deciduous, losing their leaves on the approach of winter, and so being uninjured by snow. In New Zealand, out of the 1,415 species of flowering-plants 450 (or 31.8 per cent.) were trees or shrubs. Of this number, 398 (or 88.3 per cent) were evergreen, 45 (or 10.1 per cent.) were leafless, while only 2 species of Euchsia were absolutely, and 5 other plants partially, deciduous—that is, at the outside, less than 1.5 per cent. were fitted to withstand the destructive effects of snow. In the face of these facts it is impossible to conceive that this Island had a glacial epoch within recent times. (3.) There exists in New Zealand, and especially in the South Island, what is called a xerophytic or desert flora—a group of plants specially modified to withstand drought. These are principally found on the mountain-slopes and on the plains on the eastern side of the main range of mountains forming the backbone of the South Island. The speaker showed the effects of this range on the moisture-laden winds which strike the

west coast, causing precipitation of their moisture on the west side, and great dryness on the east. He also gave examples of the small amount of moisture which the desert plants lost by evaporation, and stated that, roughly speaking, about 220 species of flowering-plants, found in the inland parts of the Island, belong to this category. He argued that such a flora could not have arisen since the Pleistocene epoch, but that it was probably due to an intensification of the present conditions. An elevation of 5,000 ft. of the central chain of the South Island within comparatively recent times would have been accompanied on its eastern side by an extremely dry climate, tending to the production and survival of a xerophytic flora. It would also serve to account for the glacial phenomena now visible in many parts of the country, for the formation of the great glacier-lakes, and of the West Coast Sounds, with their terminal moraines under the sea outside their entrances. Summing up all the evidence available from a consideration of the existing flora of New Zealand, he pronounced strongly against the possibility of a glacial epoch within recent geological times. Dr. Benham, treating the question from a biological point of view, said that the question of a Pleistocene ice-sheet covering New Zealand, and continuous with the extension of the polar ice-sheet, was one that had very important bearings on the character of the fauna of these Islands, and any geological evidence there might be which seemed to indicate the existence of such an ice-sheet must be correlated with biological evidence. In the case of the Northern Hemisphere the advance of the ice-sheet forced existing life to migrate to the south, whence it returned on its withdrawal. But here in the south there was no possibility of restocking the land after having been covered by the ice-sheet. The fauna of New Zealand was in many respects of a remarkable character owing to the great specialisation of its members; yet it contained descendants of ancestors which entered New Zealand at various periods from the north, by way of New Guinea and other lands. Thus it was seen that at two periods New Zealand was of much greater extent than at present—indeed, that it formed a small continent, embracing New Caledonia, the Kermadecs, Chatham Islands, and the Antarctic islands, though not necessarily at the same period. In this continental area the descendants of the immigrants became specialised, and since the last period (Pliocene at latest) there had been no communication with any other land. They knew approximately the date of separation of New Zealand from other land-surfaces—in the latter part of the Mesozoic period; when it received many of its invertebrates—probably in the early Pliocene, when it extended so far south as to include the Campbell, Auckland, and Macquarie Islands, and received its southern forms from America, by way of an Antarctic continent. It appeared that Cook Strait was formed in the later Pliocene; hence the fauna of the South Island had ever since that period been isolated from that of the North Island. A mere examination of the differences in the fauna of the two Islands—quite apart from geological evidence—would indicate that the separation had been longer than the Pleistocene, for a considerable period of time was necessary for the evolution of species. Taking as an analogy Britain, which retained its land connection with Europe till after the Ice Age, they saw that in Britain the species were practically all identical with those of Europe; but in New Zealand many of the birds were represented by distinct species in the North and South Islands—as, for instance, the Maori hen, which had one species in the North Island and three in the South Island; Notornis, which had one species in each Island; the moas, which existed down to historic times, had four different species, and even different genera, in the two Islands; and the parrakeet, crow, thrush, robin, tomtit, and weka each had distinct species in each Island. As regarded snails, slugs, and other invertebrates, the same was the case, though they lacked sufficient detailed knowledge to allow of statistics being presented. These differences imply a separation. But if the South Island were covered by an ice-sheet when the northern limit extended to Cook Strait (vide Bulletin, p. 40), all the animals of the South Island must have been wiped out. Whence did the present fauna, then, arrive ? Birds, it will be said, can fly over Cook Strait. True; but there will have been insufficient time for the differentiation of species. But such an explanation is impossible in the case of the snails, worms, spiders, and flightless insects such as the weta: these all required land connection. The earthworms of the South Island could not have been derived from those of the North Island. Perhaps Professor Park would reply that the ice-sheet left part of Marlborough uncovered; but, even if Cook Strait were not as yet in existence, we still lacked sufficient time for the differentiation of species in the two Islands. Moreover, the genera of earthworms were so greatly different that much longer time was necessary. But a still more serious difficulty was incurred when they bore in mind that this Pleistocene ice-sheet “was an extension of the polar ice-sheet” (p. 43). This polar ice-sheet must have covered Campbell and Auckland Islands—as he himself believed to have been the case—for at this time the elevation of the land in the early Pliocene placed these islands in connection with the South Island of New Zealand. This ice-sheet must

have destroyed all animals and all plants in these Islands, and, since they had not been in connection with any land-surface since the Pleistocene, it was impossible for them to have been peopled since that date. Moreover, the species of land-birds on the Auckland Islands were distinct from those of New Zealand. It was not a question merely of their annual flight after the withdrawal of the ice-sheet. That was quite possible, for several introduced birds were observed, but the differentiation of species in these outlying islands was great, and all indicated a long separation; while the presence of the flightless duck, a genus found nowhere else, was even more impressive. As a result of the recent expedition they found, from an examination of the various groups of invertebrates, that, although there were similarities to those in New Zealand, many of them were more nearly allied to South American forms, which could not by any possibility have survived an ice-sheet, or have arrived here after the ice-sheet had withdrawn. It was only possible to explain the occurrence of such existing terrestrial forms, which could neither fly nor swim, which could not survive a sea-bath, by their migration along a land-area extending across the Antarctic region from South America to these Islands. It seemed to him that the onus lay with Professor Park to show how these subantarctic islands became peopled after their fauna and flora had been wiped out by the Pleistocene ice-sheet. The whole biological evidence seemed to be entirely antagonistic to his theory. “Moreover,” he said in conclusion, “I believe that the thesis can be strongly supported that there was no general reduction of temperature over the whole Southern Hemisphere at or about that period.” Professor Marshall also criticized Professor Park's conclusions adversely, his summary and conclusions being as follows:—A. That an ice-sheet did not reach the east coast of the South Island is proved by—(1.) The absence of moraines near the coast, except at the landward end of the Taieri Gorge, where there have been important earth movements. (2.) The absence of till and boulder-clay. The substances that have been claimed as belonging to this class are—(a) loess in Canterbury and north Otago, (b) residual clays from volcanic rocks at Dunedin, (c) moraine and valley-trains at the Taieri, (d) old sea-beaches at Caversham and at Green Island. (3.) Absence of roches moutonnées. (4.) Absence of striated glacial pavements. (5.) Absence of erratics and of striated boulders. (6.) Absence of a glacial topography in all coastal districts. B. The ice of the Wakatipu glacier. (1.) The occurrence of ice in one valley does not justify the conclusion that the neighbouring valleys were ice-filled. (2.) The thickness of the ice in the ancient Wakatipu glacier appears less impressive when it is realised that the ice in the Tasman Glacier is at the present day over 2,000 ft. thick, and that its base is only 1,600 ft. above sea-level. (3.) If the ice was 7,940 ft. thick at the Hector Mountains and if it had the same surface-slope as the Greenland ice-sheet, it must have extended far over the tops of all the western mountain-peaks, which, however, are not glaciated. (4.) The reversed slope of the Wakatipu basin must have existed during the glaciation. This implies a rapid thinning, which must have been due to melting. Adopting the surface-slope of the Greenland ice-sheet, the terminal face cannot have been east of Lumsden. (5.) The author's estimate of the level of the surface of the ice is 4,000 ft. at Mount Dick. The terminal face would then be at Athol. (6.) There is no ice erosion on the Hokonui Hills, and no moraine or erratics in the Waimea Valley. C. The suggested extension of the Antarctic ice-sheet. (1.) At the present time the ice nowhere extends into deep water. (2.) There was no ice-sheet in Siberia when there was an ice-sheet in central Europe, or in Alaska when the Mississippi Valley was glaciated. (3.) America was not all glaciated simultaneously. (4.) A reduction of temperature in South Victoria Land would cause a decrease of glaciation. (5.) There is an absence of all effects of an ice-sheet at the Campbell and Auckland Islands. (6.) No erratic blocks from South Victoria Land have yet been found in New Zealand. D. The suggested glaciation of the North Island is disproved by the following: (1.) The mapping of the river courses shows no indication of the existence of a glacial topography. (2.) No striated rock-surfaces. (3.) No glacial moraines. (4.) No erratic blocks with striations. (5.) No roches moutonnées. (6.) The “boulder-clays” referred to are deposits laid down by rivers that flowed from active volcanoes during periods of activity. (7.) The deposits at different heights are due to rivers; for as the land was gradually raised the base level of erosion would lie deeper and deeper in the rocks, and portions of the older base levels would be left at various heights. (8.) No valleys with the characteristic form of those due to glacial erosion have yet been described on Ruapehu. (9.) No glacial valleys have been described in other parts of the North Island. In general the writer sees no reason to depart from the view long held by all New Zealand geologists, that the amount of Pleistocene glaciation in New Zealand did not reach to the magnitude of an ice-sheet. On the western side the ancient glaciers reached the coast in many places in the south of the South Island, while on the eastern side they threaded far through the mountain valleys towards the coast.