July 3, 1919] 



NATURE 



157 



food-fishes (with the exception of Schmidt and Peter- 

 sen on the eel) do not show much that is novel, for 

 most of these had long before been worked out from 

 ihe egg to a recognisable stage in "Scotland. 



The third report of the northern section consists of 

 a series of statistical tables of the round fishes from 

 the Aberdeen trawl fishery, 1901-6, and a report of the 

 fluctuations in the market price of fishes (Prof. D'Arcy 

 Thompson). No conclusion is arrived at in regard to 

 abundance or scarcity. The fourth report (1906-8) 

 states that recent work has greatly added to our know- 

 ledge, " though without bringing us within reach of 

 a clear statement and comprehension of the whole 

 case," and this though results were guaranteed within 

 two years. The report includes hydrographical in- 

 vestigations in the North Sea and Faroe-Shetland 

 Channel, temperatures of the surface waters of the 

 North Sea, salinity of the North Sea, and experiments 

 with drift-bottles. ITie fifth report contains observa- 

 tions on the plaice caught by the Goldseeker, supple- 

 mented by statistics from the Aberdeen market, by 

 thei same author. It is stated that large plaice have 

 diminished by two-thirds between 1905 and 191 1, 

 whilst the landings of extra small plaice (8 in.) have 

 increased threefold. No explanation is given as to 

 whether the ship worked on adult plaice grounds, or 

 whether those in the fish market represented with 

 an\- degree of trustworthiness the corresponding work 

 of the earlier period ; nor is it explained that the 

 smaller forms are now saleable, whereas formerly 

 thev were not. In any case, the removal of the larger 

 plaice by intensive fishing is the rule, but the gaps 

 thus made are filled later by the swarms of the 

 smaller. Besides, it is not stated that the search for 

 the large plaice was in the same or similar areas and 

 on the corresponding dates in each period. As already 

 indicated, the wide distribution of the plaice over the 

 North Sea is a safeguard. An able report bv Dr. 

 Fulton on the seasonal abundance of the flat-fishes in 

 the North Sea follows. He concludes that turbot and 

 brill are scarcer, halibut more numerous, large witches 

 fewer, small witches less diminished, megrims less 

 numerous, lemon-dabs (the decrease of which twentv 

 vears ago was a mainstay of impoverishment) have 

 increased, plaice have decreased, yet off Kinnaird 

 Head, a chief trawling area, small plaice have rather 

 increased, though less so than small lemon-dabs and 

 witches. An interesting and laborious report is given 

 by the same author on the marking of plaice in con- 

 nection with their migration, growth, and other 

 features. The adult plaice seemed to travel further 

 than the immature, and often against the current 

 from the north, so that he was inclined to connect 

 this with their reproduction, the eggs and larvae being 

 thus carried southwards ; but such may be capable of 

 other interpretations. At any rate, large plaice occur 

 all along the eastern deep waters, and produce eggs 

 and larvae which pass shorewards there. Other 

 papers are on egg-production of numerous fishes by 

 Miss A. Mitchell, statistics of trawled fishes landed 

 at .\berdeen, and a report on hvdrographical in- 

 stigations (19 13).. The fishery statistics of the world 

 : 191 1 and 1912 were given by Prof. D'Arcy Thomp- 

 n in 1917. though the relation of this compilation to 

 ! task set before the International Council is not 

 vident. The main fact is the prominence of Great 

 Britain amongst the twelve countries selected. The 

 preponderance of the total catch of fishes, moreover, in 

 the North Sea is noteworthy, and bears out H. M. 

 Kyle's view that there has been no diniimitiiMi in 

 the yield of the North Sea between 1907 and 1912. 

 It would have been interesting to compare these with 

 the fisheries of the United States and of the great 

 British Colonies of Canada, Australia, and New Zea- 

 land. Other statistical papers, such as those on the 

 NO. 2592, VOL. 103] 



Aberdeen trawl industry, by the same author, and by 

 Helland-Hansen on the cod and haddock, need only 

 be mentioned. They do not affect the general 

 question. 



The work of the trained scientific staff of the 

 Fishery Board for Scotland, again, and independently 

 of the International Council, has for many years been 

 worthy of all praise. The researches of Dr. Fulton 

 on the plaice and other flat-fishes, on the rate of 

 growth and the food of fishes, their migrations, dis- 

 tribution, fecundity, ovarian eggs, and spawning, are 

 both numerous and important. His reports on trawl- 

 ing, line fishing, herring fishing, and on the hatchery 

 at Nigg still further add to our knowledge. The able 

 work of Dr. H. C. Williamson is also equally credit- 

 able to the Board, and ranges over the various food- 

 fishes, adult and voung, edible crabs and shell-fishes, 

 as well as includes interesting experiments on the 

 effect of cold in connection with the transportation 

 of fishes' eggs to distant regions, such as Australia. 

 Dr. Thomas Scott ably took in hand the floating 

 fauna, crustacean and annelidan parasites of fishes, 

 the food of marine fishes, and the fauna of fresh- 

 water lochs. Mr. Harold Dannerig managed the 

 hatcherv at Dunbar, and for a few years that at 

 Nigg until he left for an important fishery post in 

 New South Wales; but, unfortunately, this trained 

 fisheries worker perished with the fishery research 

 ship of the Commonwealth. Besides these, the 

 talented George Brook, Prof. Milroy, of Belfast. Dr. 

 H M Kvle, J. T. Cunningham, Dr. A. G. Anderson, 

 Mr. E. W. Shann, and Dr. Bowman have all con- 

 tributed to our knowledge of the fisheries. 



In addition to the international work, the Danish 

 Government carried cut, bv means of its vessel Thor, 

 various independent observations. Thus Johansen 

 (1907) marked numerous plaice, and found that growth 

 was most rapid up to the third year, but on approach- 

 ing maturity it was slower. He thought adult plaice 

 sought the shallow water in spring and autumn 

 (which has not been verified as yet in Britain), and 

 that their rate of progress was from two to six miles 

 a dav. Johannes Schmidt, again, marked many cod 

 in Icelandic waters, where thev spawn chiefly off 

 the south and south-west coasts in warmer water, for 

 a polar current keeps the north and north-east shores 

 cold through the vear. In summer a branch of the 

 warm current moves eastwards along the north coast, 

 and he thinks it is important for young fish-hfe, since 

 the voung swarm in the fjords of the north and north- 

 east^ yet thev pass the winter there, notwithstanding 

 the temperature. He was of opinion that the mature 

 plaice, which he also marked, migrated to reach 

 warmer water for spawning, but he was uncertain 

 of this in regard to the cod. He concluded by sup- 

 posing that at the spawning period fishes generallv 

 require definite conditions of temperature and depth, 

 whilst at other times they are indifferent to these. 

 The same author describes the larval stages of various 

 fishes, as also did C. J. Petersen. Semundsen 

 (1013), from marking experiments, thought that both 

 plaice and cod kept to Icelandic waters. Changes in 

 the specific gravity of the floating eggs are noted by 

 Tacobson and Johansen (1900); the latter also con- 

 tributed several papers on the plaice, such as varia- 

 tions in the frequcncv of voung plaice in Danish 

 waters (1Q08). He could not sav definitely that a low 

 salinitv of surface water caused a deficiency of young 

 plaice in IQ04, and is not sure but that a low tem- 

 nerature might be prejudicial to er^r^s and young. 

 Papers of outstanding merit arc contributed by Jobs. 

 Schmidt on the metamorphosis and distribution of the 

 larvfe of the eel on the occurrence of voung eels 

 (Leptocephali) in the Atlantic west of Europe, and on 

 the distribution and classification of fresh-water eels 



