September q, 1909] 



NA TURE 



321 



They happened to run across Mr. Bentham, the great 

 authority upon the classification of plants. Sir Joseph 

 introduced him to the President, adding, " he works in 

 our herbarium." " Dear me," said the President, " I 

 hope you don't get your feet wet." Now I do not want 

 for a moment to suggest that our present genial President 

 of the Board of Works — whose official connection with 

 Kew has been long severed — would not readily distinguish 

 between an herbarium and an aquarium, but what I do 

 wish to emphasise is that this ignorance of some of the 

 most elementary details of scientific method exists in many 

 of our rulers and in many of our permanent oflficials — not 

 in all by any means ; I know of some most notable excep- 

 tions — but in many. It is but human to distrust what 

 we cannot understand, and it is this lack of understanding 

 which is largely retarding progress at the present day. 



III. 

 Jnteniaiioiial Ocean Research. 



.'\s an example of international cooperation in scientific 

 research I may take the investigations which have been 

 going on for the last seven years in the Baltic Sea, in 

 the North Sea, and in that greater Norwegian Sea which 

 stretches from the western coast of Norway north to 

 Spitsbergen and westward beyond Iceland and the Faroes. 

 In this inquirv no fewer than ten nations — in fact, all those 

 the shores of which touch these seas — have had a share 

 — England, Scotland, Norway, Sweden, Finland, Russia, 

 Germany, Denmark, Holland, and Belgium — and since 

 most of these countries have a special steamer equipped 

 for research and under the command of men trained in 

 scientific methods, it has been possible to collect a mass 

 of facts connected with the seas of Northern Europe such 

 as has never been got together before for any similar 

 area of the ocean. 



The aim of those responsible for the scheme of work 

 was to obtain as complete a survey as possible of the 

 physical and biological conditions of the seas in question. 

 They wanted to know the direction of ocean currents, 

 both superficial and along the bottom ; the variations in 

 the degree of salinity of the water in time and in space ; 

 the nature of the sea-bottom, and whether this could be 

 correlated with the fauna, sessile or moving, found upon 

 it, and whether this fauna reacted on the prevalence or 

 absence of food-fishes ; the influence of depth, salinity, 

 and temperature on the fauna ; the seasonal variations 

 and fluctuations of the small floating organisms often called 

 the plankton ; the life-history of our food-fishes, where and 

 when they deposited their ova ; what became of the ova ; 

 the distribution of the larval stages ; the age at which 

 the fish become mature, and their average length of life. 



Then, again, it was hoped that much could be learned 

 about the influence of man's activity on the sea. The 

 relative depletion of the fish population caused by different 

 modes of fishing ; the intensity of trawling ; how often 

 does the trawl pass over the same ground in a given 

 time? The question whether or no the seas are being 

 over-fished, and, if so, what measures can be taken to 

 lessen this evil, either by close time, limiting the size of 

 fish captured, or by artificial fish-breeding. Many of these 

 last-named problems concern the legislator as much as 

 the man of science. The function of the latter is to pro- 

 vide facts upon which the administrator mav act. 



Such a vast task as was set out by the International 

 Council in 1902 has necessitated an immense organisation. 

 Some eight or ten steamers are emploved making periodic 

 voyages, under the direction of trained men of science. 

 Enormous numbers of temperature-readings, investigations 

 into the speed and direction of currents, and chemical 

 analyses of sea-water have been recorded, and thousands 

 of samples of the bottom, of the animals and plants living 

 thereon, of fish in all stages, millions of fish ova, have 

 been collected and accurately determined. To work up 

 such an amount of material has occupied the attention 

 of a large number of naturalists. Each country has at 

 least one large laboratory devoted to this work, and their 

 results are coordinated and generalised by the central 

 bureau. The English part of the work was entrusted by 

 the Lords of the Treasury to the Marine Biological .Associa- 

 tion, and has been carried out under the direction of Dr. 



NO. 2080, VOL. 81] 



E. J. Alien and Prof. Walter Garstang at our laboratories 

 at Plymouth and Lowestoft. 



Although all the ten countries are working upon what, 

 is, broadly speaking, a common plan, each has had its 

 own special problems. In addition to carrying out the 

 broad outlines of an international scheme, they have 

 specialised along lines indicated by their own needs, and. 

 have attacked problems the solution of which affected their 

 own special food supply. Thus Norway, where the oldi 

 open fishing-boat is being replaced by the modern, decked 

 trawler, has especially studied the cod and the saithe, 

 the haddock and the herring, and has devoted much time- 

 and labour to the discovery of new fishing grounds, and' 

 has successfully done this along the Norse coast, in the 

 Arctic circle, and on the banks between the Faerde Islands 

 and Iceland. . They have further established a trade in. 

 Pandalus borealis, allied to the prawns, which are taken 

 in the deep waters off Norway, and are now to be bought 

 in most fishmongers' shops in Great Britain. 



In a similar way the Danes have tracked the eels as. 

 they leave the estuaries of the great rivers of Central 

 Europe across the North Sea to the deep Atlantic off the 

 West of Ireland, just beyond the looo-fathom line. In' 

 these depths they spawn, and the resulting larval form, 

 the Leptocephalus, long thought to be a separate genus, 

 lives there for a while, until, gradually changing into an 

 elver, it retraces by some mysterious instinct its parents'' 

 path across the ocean and regains the fresh-water rivers 

 which those parents had left. 



The English share of the investigation is limited to that 

 part of the North Sea which lies south of the latitude of 

 Berwick, and for the most part to the western half of 

 these seas and to the English Channel ; the latter, as we 

 shall see, is a very important area. The work, so far as 

 it has been specialised, deals, in the North Sea, largely 

 with the plaice, with the food of fishes generally, and 

 with the character of the deposits forming the sea-floor, 

 with the creatures growing thereon. In the Channel the 

 English worker is entirely responsible for the study of 

 the hydrography of the water, which, entering the North 

 Sea through the Straits of Dover, contributes greatly to 

 its mass. 



As a result of Prof. Garstang's investigations, an 

 important spawning ground of the plaice has been located 

 in the southern bight of the North Sea ; the migration of 

 both sexes has been traced to these grounds on the advent 

 of the spawning season, and their return to their feeding 

 grounds in the spring has been followed. During the 

 spawning season it is usual to catch more males than 

 females on the spawning grounds, possibly because at this 

 time the female is inert and elusive, whilst the male is 

 unusually active. 



The course of the ova has been traced, chiefly by the 

 Dutch investigators, as they drift towards the shallow- 

 fringe of coastal water, by far the greater number along 

 the continental coast. Here the young fry grow up, and 

 after attaining a certain size they leave the shallow coastal 

 waters for the deeper seas off shore. Comparatively few 

 of these, however, reach the feeding ground of the Dogger 

 Bank, and Garstang has been able to show that by carry- 

 ing the young plaice in steamers and transplanting them at 

 the proper time on to this rich feeding ground, their rate 

 of growth can be greatly accelerated and thus their market 

 value largely increased, just as Dr. Petersen has done in 

 the case of plaice on Thisted Bredning. 



.\ few vears ago there was no trustworthy method of 

 determining the age of fish. Petersen's method of 

 arranging the measurements of a large number of speci- 

 mens in a scale according to size, when they_ resolved' 

 themselves into certain groups, which were considered to 

 coincide with age-classes, has been superseded by the dis- 

 covery of ReibJsch, Heincke, and others, that many of 

 the bones, the scales, and the otoliths of fishes show annual 

 age-rings, like those found in the trunk of a tree or in 

 the horns of cattle. Bv laboriously counting the rings on 

 the otoliths of thousands of plaice. Dr. Wallace and others 

 have been able to determine their rate of growth, and to 

 show that some specimens attain the age of twenty-five- 

 and even twenty-nine vears. Similar investigations have 

 shown that the sexes 'have a different rate of growth. 

 The age at maturity is found to differ in different regions. 



