OUTLOOK 



^ ScHRADER, F., Biol. Bull., 67 (1934), 519 



* Darlington, C, Proc. roy. Soc. Lond. b, 121 (1936), 264 



* Cleveland, L. R., Science, 81 (1935), 598 



* Loveless, A. and Revell, S., Nature, 164 (1949), 938 



' White, M. J. D., in Cytology and Cell Physiology, Ed. by BournCj G., ist ed,, 

 Oxford, 1942, p 152 



* Bateson, B., William Bateson, Naturalist, p 324, Cambridge, 1928 



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