June 22, 1917] 



SCIENCE 



629 



clothing', woodwork and other manufactured 

 products. 



2. Application of principles of heredity to 

 the improvement of breeds of domestic animals. 



3. Study of physiology of reproduction with 

 a view to increasing productivity in animal 

 breeding; for example, improved methods of 

 incubation, brooding and rearing of fowls. 



4. Determination of standards of feeding 

 and nurture of domestic animals for best gen- 

 eral or specific results and for greater economy. 



III. EXTENSION OF FOOD SUPPLY 



1. Preservation, propagation and domestica- 

 tion of useful wild animals. Probably certain 

 useful birds and mammals, now wild, might be 

 domesticated; others not native might be im- 

 ported under proper precautions. 



2. The protection of birds which are bene- 

 ficial to agriculture. It is estimated that in 

 Kansas alone the annual preventable damage 

 to food crops amounts to thirty million dol- 

 lars. The largest natural elements in the pre- 

 vention of this loss are ground-nesting birds. 

 Migratory birds should be protected by the 

 passage of the House of Representatives Bill 

 No. 2612, known as the " Migratory Bird 

 Treaty Act." 



3. Exploitation and propagation of useful 

 marine and fresh-water animals, in coopera- 

 tion with the Bureau of Fisheries. There is 

 an unlimited supply of food in the oceans of 

 the world and we have scarcely begun to reap 

 the " harvest of the seas." Countless forms of 

 fishes, Crustacea, mollusks and other types 

 which are not now generally used as food are 

 both wholesome and delicious when properly 

 prepared. The Commissioner of Fisheries 

 says: 



Zoologists may perform a service by bringing to 

 the attention of people, in the course of their con- 

 versations, lectures, etc., the reasons for looking to 

 the fisheries for increased food supply, the whole- 

 some character of the meat, the economy with 

 which fish are produced without dependence upon 

 agriculture for their food. Many new fishes are 

 being introduced into the market — sharks, bowfin, 

 burbot, sable-fish and others, and it is certain that 

 zoologists can do a good service in helping to over- 

 come popular inertia that will be encountered. 



The Bureau will gladly send circulars announcing 

 new fishes to any who apply. 



The biological problems of fish ponds are nu- 

 merous. Eecently a college zoologist in associa- 

 tion with the Bureau began giving special attention 

 to the relation of dragon flies and damsel flies to 

 fish culture in ponds. Already he has gained re- 

 sults that were unexpected, but that are highly 

 significant. The larvas of dragon flies were known 

 to prey upon fish fry, but this investigator. Pro- 

 fessor C. B. Wilson, finds that they also prey in 

 greater measure upon other insects that are more 

 effective enemies of fish fry; various other inter- 

 esting interrelations are discovered This is only 

 an illustration of what may be done with various 

 groups of aquatic and semi-aquatic animals and 

 plants. Results of value may, in some cases, be ob- 

 tainable in a brief space of time. 



We know very little about the parasites of 

 fishes, their relative abundance under difEerent con- 

 ditions of environment, their life-histories and al- 

 ternate hosts. Means of control can not be de- 

 vised without more complete knowledge regarding 

 particular species. 



We should be glad to advise either directly or 

 through you with any zoologist who is considering 

 a particular problem related to the fisheries. 



IV. EDUCATIONAL AND SOCL\L WORK 



1. Thorough studies of human heredity as a 

 necessary preliminary to any attempt to per- 

 manently improve our human stock and in- 

 crease national efficiency. 



2. The teaching of zoology, as well as of 

 other sciences, may be made a very important 

 means of promoting national intelligence, co- 

 operation and welfare. 



3. While the great demands on medical men 

 last, zoologists would be well qualified to assist 

 in medical education, especially in histology, 

 embryology and neurology. 



4. The prosecution of research work, 

 whether in pure or applied science, is a na- 

 tional duty of the first magnitude; the contin- 

 uance of research work by zoologists, and espe- 

 cially work already begun which can not be 

 interrupted without serious loss to science, is a 

 real national service. 



V. MISCELLANEOUS PROBLEMS 



In addition to these general lines of work 

 the following special problems have been sug- 

 gested : 



