Under the general editorship of the Commission of the Academy of Sciences USSR 

 for publishing popular scientific literature 



Chairman of the Commission, President, Academy of Sciences, USSR 



Academician S. I. VAVILOV 



Deputy Chairman, Corresponding Member, Academy of Sciences, USSR 



P. F. YUDIN 



EDITOR-IN-CHIEF 



Corresponding member, Academy of Sciences, USSR 

 L. A. IVANOV 



ACADEMY OF SCIENCES, USSR 



Moscow -19 46-Leningrad 



Copyrighf I960 by 



American Insfifufe of Biological Sciences 



iihrary of Congress 



Cafolog Number. 60-J4907 



A\\ orders should be addressed to: 



AMERICAN INSTITUTE OF BIOLOGICAL SCIENCES 



2000 P Sfreef, N. W. Wasliingfon 6, D. C 



