May 4, 191 1] 



NATURE 



Z^l 



sponsible for the great bulk of the plaice landed at 

 Ostend at the present day. Now it is clearly shown 

 that this increase in the proportion of small lish is 

 not due to a change in the field of action of the 

 boats concerned, for the displacement which has 

 actually occurred has been of such a nature that it 

 ought to have produced a contrary effect. It is in 

 consequence of a modification of the composition of 

 the reserves of plaice inhabiting the Southern Bight 

 of the North Sea. The curves for the various divi- 

 sions of the Southern North Sea show this very 

 clearly. The proportion of small fish in the annual 

 catches in each of these divisions shows a gradual 

 rise from 1904 to 1908. That the change in the com- 

 position of the plaice population on these fishing 

 grounds consists in a diminution in the number of 

 large individuals andJiof in an increase in the number 

 of small is also fairly clear. 



This is the important point : the supply of plaice 

 in the Belgian market is apparently being maintained 

 at the sacrifice* of an increasing proportion of the 

 smaller and much less valuable sizes. Researches on 

 similar lines which have been made by the other four 

 nations most interested have apparently much the 

 same tale to tell ; but, as these have not been co- 

 ordinated and compared, it would be premature to 

 make any general statement about the condition of 

 the plaice fishery in the North Sea as a whole. 



.\s a remedy for the state of things revealed in the 

 Belgian statistics, Prof. Gilson suggests the tentative 

 imposition of a minimum size of 23 centimetres, 

 below which it should be illegal on 'the part of the 

 sailing trawlers to land or sell fish, and a similar 

 standard of 25 centimetres for steam trawlers. The 

 i:easons for the selection of these particular size limits 

 and for a distinction between the two classes of 

 vessels in this respect are fully discussed in the report 

 and hardly need be recapitulated. Verv similar size 

 limits for plaice have been suggested by certain of 

 Prof. Gilson's colleagues on the International Council, 

 who will probably be found unanimous in agreeing 

 with him that all such measures designed for the 

 protection of undersized plaice should be of an experi- 

 mental and elastic nature. In view of the still verv 

 incomplete state of our knowledge of the plaice 

 problem, which is far more complex than was at first 

 supposed, certainly no State would be justified in 

 makinf such legislation final or irrevocable. It 

 would be impossible to predict the effect of the im- 

 position of a given size limit, or the amount of 

 inconvenience attending its enforcement. It is in- 

 evitably a case of "try and see." Moreover, a size 

 limit is not the only possible means of bettering the 

 plaice fishery. Transplantation to the Dogger Bank, 

 and other grounds richer in food, has been tried on an 

 experimental scale with striking results, in view of 

 which it is worth considering as a possible commer- 

 cial enterprise. 



Finally, one cannot but agree with Prof. Gilson 

 that if we are ever to have experimental legislation 

 for plaice, then it is clear that the scientific control 

 of its effects is indispensable. In other words, there 

 ought to be a permanent International Commission to 

 continue researches on points not yet elucidated, to 

 study the statistics from year to year, and to carrv 

 out biological investigations designed to show 

 the changes in the composition of the plaice 

 population on the fishing grounds and in the 

 rate of growth of the fishes which might be expected 

 to result from the legislation. As Prof. Gilson 

 truly says: "C'est i\ rv prix seulement que Ton 

 peut fspi'rer de r^parer le mal accompli et de porter 

 reni6de k la rupture encore r<^cente de l¥quilibre qui 

 NO. 2166, VOL. 86] 



s'etait etabli, au cours des siecles, entre la puissance 

 alimentaire des mers, le pouvoir reproducteur des 

 esp^ces et les causes de destruction aux quelles celles- 

 ci etaient soumises avant I'intervention de I'homme." 



William Wall.^ce. 



NOTES. 

 Mr. a. E. Smipley, F.R.S., has been elected a foreign 

 corresponding member of the Helminthological Society of 

 Washington. 



We regret to announce the death, on April 15, at 

 seventy-nine years of age, of Prof. J. Bosscha, corre- 

 spondant of the physics section of the Paris Academy of 

 Sciences, and formerly permanent secretary of the Dutch 

 Society of Sciences at Haarlem. 



The National Geographical Society of America is sending 

 out in the summer an expedition for the further study of 

 the glaciers of Alaska. It will be led by Prof. Ralph S. 

 Tarr, of Cornell University, and Prof. Martin, of the 

 University of Wisconsin. 



An expedition, under the charge of Prof. Homer R. Dill, 

 taxidermist of the University of Iowa, has left San Fran- 

 cisco for Layson Island. This island, which is situated in 

 the Pacific about midway between California and Japan, is 

 only about three and a half square miles in area, but is 

 estimated to support a bird population of about eight 

 millions. 



The tenth International Congress of Geography will be 

 held at Rome on October 15 and the six following days. 

 P^xcursions in northern and central Italy, as well as 

 southern Italy and Sicily, will be arranged, of which the 

 details will be published later. The subscription for 

 membership of the congress is il., and all persons desirous 

 of joining are requested to remit this sum at an early date 

 to the treasurer of the committee, 102 Via del Plebescito, 

 Rome. 



The Victoria Leag^ue has in operation a scheme for 

 sending newspapers and magazines, when done with, to 

 addresses in distant parts of the Empire. Alrhough more 

 than 81,000 newspapers and magazines are being sent away 

 annually there are still many applicants unprovided for, and 

 in South Africa and Victoria, Australia, particularly, we 

 are informed copies of Nature would be gratefully received. 

 Any reader willing to help the movement should apply to 

 the hon. se.c. of the Newspaper Scheme, 2 Millbank House, 

 Wood Street, Westminster, S.W» 



Ffwf. Hans Meyer will undertake in May his fourth 

 journey in East Africa. Starting from Bukoba, on the 

 west shore of Lake Victoria, he proposes to march to Lake 

 Kiva and the Kirunga group of volcanoes, in order to study 

 the relations of the volcanic phenomena to the tectonic 

 structure of the western rift system at this point. From 

 Kiva the .xijedition will travel by Lake Tanganyika and, 

 if time permits, also to Lake Nyassa. Besides geological 

 studies, the botany, zoology, and ethnology of the region 

 traversed will also be investigated. 



Dr. Pock, in the .'\pril number of I'rtcrDiaiiii's Mitlril- 

 ungcn, discusses the distribution of plague during recent 

 years, and illustrates it by two maps. The first shows the 

 location of areas where it is endemic, and also those over 

 which it has recently spread, as well as the places where 

 isolated eases have occurred in different years. The second 

 map shows the probable area of origin of the recent out- 

 break in Manchuria, and the region which was affectfd. 



