82 GENETICS 



4. Page 73. F. R. LilHe (1917), The Free-Martin: A Study of the 

 Action of Sex Hormones in the Foetal Life of Cattle. Journal of Ex- 

 perimental Zoology, vol. 23, pp. 371-451. 



5. Page 76. T, H. Morgan (1909), A Biological and Cytological 

 Study of Sex Determination in Phylloxerans and Aphids. Journal of 

 Experimental Zoology, vol. 7, pp. 239-353. 



6. Page 78. See T. H. Morgan and C. B. Bridges (1919), The 

 Origin of Gynandromorphs. Carn. Inst. Publ. No. 278 pp. I— 122. 



7. Page 79. See H. N. Gould (191 7), Studies on Sex in the Her- 

 maphrodite Mollusk Crepidula plana. II. Influence of Environment 

 on Sex. Journal of Experimental Zoology, vol. 23, pp. 225—250. 



8. Page 79. See F. Baltzer (1925), Untersuchungen ither die Ent- 

 wicklung und Geschlechtsbestimmung der Bonellia. Pubblicazioni della 

 Stazione Zoologica di Napoli, vol. 6, pp. 225-286. 



9. Page 80. Accounts of many of these different conditions as to sex 

 will be found in Goldschmidt's The Mechanism and Physiology of 

 Sex Determination^ referred to in Note I, above. 



