30 U. S. BUREAU OF FISHERIES. 



undoubtedly serve a useful purpose in promoting the utilization of 

 an available source of food and therebj^ will contribute to the pre- 

 vention of waste of the Nation's food supply. 



UTILIZATION or FROGS. 



The daily correspondence of the Bureau has indicated for a long 

 time the widespread interest in frogs, their utilization and prop- 

 agation, and their elimination from localities where they are not 

 desired. Nevertheless the Bureau has not yet felt justified in divert- 

 ing to experiments in frog culture facilities which are required for 

 other useful purposes, especially in view of the extensive natural 

 resources in frogs which are not now fully availed of. It has been 

 deemed distinctly worth while, however, to acquire as full knowledge 

 as possible of the useful species, their habits, conditions of life, breed- 

 ing, life history, food, and enemies, as well as of the methods of 

 capture employed. The report by Dr. A. H. Wright, temporary in- 

 vestigator, went to press during the year.*^ With this handbook the 

 frog fisher or the prospective frog-culturist may readily identify the 

 frogs in any stage — eggs, larvse, tadpoles, or adults — and may be 

 guided in the selection of environments for fishing or propagation. 



THE BIOLOGICAL LABORATORIES. 



The Navy Department having withdraAvn from the Woods Hole 

 (Mass.) station, the laboratory was reopened at the beginning of the 

 fiscal year, Avith Dr. P. H. Mitchell as director. With a limited staff, 

 investigations were pursued with reference t'o oysters (p. 21), gelatin 

 from seaw^eeds (p. 29), the reddening of salt fish (p. 27), and the 

 food and the parasites of fishes (pp. 19 and 18), the results of which 

 have previously been indicated. Some experiments were also con- 

 ducted by Dr. F, E. Chidester to determine vSome of the factors which 

 influence the migrations of fishes and the behavior of fish in presence 

 of certain chemicals. A miniature river system was employed, in 

 which the fish were given a choice between two tributaries having 

 water supply of different nature or current of different rates. It was 

 found that the behavior of the fish varied according to season or con- 

 dition of the animal, and particularly according to the rate of flow 

 of the water; but — given a proper condition of stream flow, the first 

 were repelled by some salts and attracted by others. The results will 

 be published after further experiments are made. 



The Beaufort (N. C.) laboratory, after occupancy by the Navy, 

 since January, 1918, was turned over to the Bureau of Fisheries 

 shortly after the beginning of the fiscal year. Since that time many 

 necessary repairs and renewals have been made both by the Navy 

 Department and by this Bureau. The date of the station's return pre- 

 vented its opening on the usual scale for investigational work during 

 the summer and fall. Small salaries have tended to malring the 

 personnel changeable and have prohibited the beginning of any broad 

 investigational project. O. W. Hyman served as acting director 

 during the summer and until the director, R. L. Barney, who was still 



"Wright, A. H. Frogs: Their Natural and Utilization. Appendix VI, Report, 

 U. S. Commissioner of Fisheries, 1919, 44 pp. Washington, 1920. 



