October 30, 1890] 



NATURE 



653 



representing the facts at the time, they go far toward explaining 

 one of the greatest difficulties against the acceptance of the 

 hypothesis that the waters by which the plains were flooded were 

 in communication with those of the sea. The difficulty alluded 

 to is the complete absence, so far as yet ascertained, of the 

 remains of marine organisms from the glacial deposits. While 

 ;irolonged weathering and the action of sub-aerial waters might 

 suit in the removal of calcareous organic remains from certain 

 u ts of these deposits, the condition of much of the boulder- 

 ly, together with the occasional actual occurrences in it of 

 1 1 agments of Cretaceous or Laramie shells, is such as to show 

 that any contemporaneous mollusks might have been preserved. 

 If, however, the body of water in question, though communi- 

 cating with the sea to the northward, was almost throughout 

 closed to the south and in receipt of large quantities of fluvial 

 water, it may well have been in great part brackish, if not 

 almost entirely fresh. Adding to this the conception of its 

 frigid temperature due to the great abundance of ice with which 

 it must have been laden, and the vast amount of fine sediment 

 which must have been carried into it by sub-glacier streams, it 

 will be apparent that the conditions were singularly inimical to 

 the existence of life of any kind, whether that characteristic of 

 salt or fresh water. Somewhat similar conditions, though on a 

 much smaller scale and without the adjunct of glacial waters or 

 glaciers, occur in the southern extremity of Hudson Bay, where, 

 as Mr. A. P. Low informs me, marine life is almost entirely 

 absent, the water being nearly fresh and clouded with mud 

 derived from the large entering rivers and from the action of the 

 waves upon the shallow earthy shores." 



Finally the climatal conditions deducible from the geological 

 facts coincide with these facts in enforcing the probability that 

 the great ice age of North America depended mainly on the 

 existence of high mountains, surrounded by submerged areas, 

 traversed by ice-laden currents, and that we are to imagine, not 

 a continent covered with ice, but a submerged continent, with 

 ^now-clad mountains rising at its margins, and forming the 

 gathering grounds of great local glaciers — the Cordilleran, the 

 Laurentide, and probably the Appalachian glaciers. These 

 were the favouring conditions, but the author does not venture 

 to deny the co-operation of other and cosmical causes. He 

 concludes as follows : — 



" When the study of the superficial deposits of different parts 

 of Europe and America was for the first time seriously begun, 

 it was endeavoured to explain the phenomena entirely by 

 diluvial action, and when the evidence of ice-action became 

 insuperable, icebergs and floating ice only were at first admitted 

 as factors. Since that time the pendulum of opinion appears to 

 have swung to the opposite extreme, and the energies of the 

 majority of investigators have been extended in endeavouring to 

 account for the varied facts of what has become definitely known 

 as the Glacial period, almost exclusively by the action of great 

 confluent glaciers. From this extreme point, the pendulum 

 may now be supposed to have returned so far, as to leave the 

 hypothetical North Polar ice-cap almost without an advocate, 

 but at what position it may eventually come to rest time alone 

 can decide. I am aware that some of those who have accepted 

 what I may perhaps be pardoned for characterizing as extreme 

 views as to glacier action, have more or less completely, and to 

 their own satisfaction at least, solved all difficulties opposed to 

 the action of land ice, such as those presented by the facts met 

 with over the Great Plains, by the application to these of their 

 single universal menstruum. For myself I need only say that I 

 have endeavoured to approach the subject of the glaciation of 

 the north-western part of the continent, here reviewed, un- 

 trammelled by a priori theories, and with some personal fami- 

 liarity in the field with nearly all parts of the region dealt with." 

 The above is only a hurried and imperfect summary. The 

 paper itself, as containing the matured conclusions of long and 

 thorough investigation by an able and earnest explorer, should 

 be carefully read by all interested in the structure of the Great 

 Cordilleran backbone of the American continent. 



THE SCIENTIFIC INVESTIGATIONS OF THE 



FISHERY BOARD FOR SCOTLAND?- 

 T^HE results of the scientific investigations for 1889 are given 

 -*■ in full detail with numerous tables and two charts. It 

 was found that, during the year, no increase but rather a decrease, 



' " Eighth Annual Report of the Fishery Board for Scotland." Part III. 

 Scientific Investigations. 



mainlyjin the migratory round fishes, occurred in the closed 

 waters, and likewise in the open waters adjacent, the results of 

 1887 having been proved exceptional. The results of con- 

 current investigations carried on on board the Gariand into the 

 food of fishes, their spawning, and the distribution of the young, 

 show that great and important diflTerences — which must be taken 

 into consideration both from a scientific and legislative point 

 of view — prevail among the various food-fishes (Section A). 



Dr. Wemyss Fulton, in his paper on the distribution of im- 

 mature sea-fish and their capture by various modes of fishing, 

 gives the results of the investigations into this important subject. 

 The fundamental question as to what an immature fish is, has 

 been determined for the first time by the examination and 

 measurement of 13,000 fishes. The maximum size (as given in 

 detailed tables) varies very much according to the species ; any 

 law regulating the legal sale of fish on the principle of size is 

 therefore not based on scientific data. The distribution differs 

 in the same way, but territorial waters serve as nurseries for the 

 young fish. Tables given show the distribution of immature 

 fishes at distances from the shore up to 22 miles and in various 

 depths of water. Details are also given as to the proportion of 

 immature food-fishes captured by the various modes of fishing. 

 Dealing practically with the wasteful destruction of immature 

 food-fishes. Dr. Fulton points out the difficulty of deciding 

 among the different species, and shows how difficult it will be 

 to save immature fish from capture and destruction by the beam- 

 trawl, as that engine is now employed. The recommendations 

 briefly are : that an inquiry should be made as to the retention 

 of vitality by the various kinds of immature fish brought up in 

 the trawl in order to ascertain the chances of survival if replaced 

 in the sea ; the protection of nurseries whose areas are capable 

 of definition ; the preservation of flat-fish under a certain size ; 

 and the establishment of hatcheries for sea- fish. A simple 

 method is explained by which fishermen and trawlers might 

 add to the fish-supply by fertilizing the ova of ripe fish when 

 captured. 



Regarding this Report, it should be noted that the importance 

 of this question is not a thing which has dawned upon the Scottish 

 Fishery Board since the conduct of scientific investigations was 

 placed under new management (that of Dr. Fulton). In this 

 paper, as in many others — indeed, everywhere in this year's 

 Report — the willingness to ignore all that was done during the 

 years that Prof. Ewart was convener of the Scientific Com- 

 mittee is very evident. In the Report of 1887 it is stated that 

 *' We have organized a series of extensive and systematic in- 

 quiries into the conditions of the reproductive organs of various 

 kinds of fishes throughout the entire year, with particulars as to 

 their size, &c. , tvhich ivill help to clear up the hitherto obscure 

 problems as to the minimum size of sexually mature individuals, 

 j dT'c." We have certain information that the original discoveries 

 which led to this Report on immature fish were made by one 

 ! who has done more than his share to redeem the work of the 

 ! Fishery Board. And it is only fair that the credit which is Mr. 

 T. Scott's due, and which is denied him there should be 

 acknowledged here. 



Dr. Fullarton furnishes a Report, with chart, on the cockle- 

 beds of Barra (in the Hebrides), which furnishes the chief 

 cockle-fishing in Scotland. It is desirable — and the wish of the 

 i fishermen themselves — that means should be taken to prevent 

 i the taking of undersized cockles, and to insure the working of 

 j the beds in rotation. 



Dr. Fullarton also gives a paper on oyster-culture fauna in 

 France and Holland. It is most desirable that scientific and 

 practical measures should be taken to revive the Scotch oyster- 

 fishing, which has gradually declined, and these should be 

 planned on known and tried lines. The same must be said of 

 the cultivation of mussels, and this should be urged even more 

 strongly, as their scarcity or abundance are of the utmost im- 

 portance to the line-fisherraen. Lobsters also call for practical 

 legislation and artificial cultivation. The Fishery Board are 

 constructing a lobster inclosure at Brodwick, Arran, and hope 

 that means will be provided for their carrying on operations at 

 the recently established hatchery at Dunbar. 



Section B contains the biological investigations. The food 

 of fishes was dealt with in an elaborate Report by Mr. Ramsay 

 Smith, based upon the examination of many thousand food- 

 fishes which prove to live chiefly upon Crustacea, Annelids, 

 Echinoderms, Mollusks, and upon one another. There are great 

 differences, however, as to the proportion of the organisms 

 selected as food by different fishes, and the proportions of the 



NO. 1096, VOL. 42] 



