LECTURES IN BIOLOGICAL SCIENCES 



Mahadevan, P. 1954. The improvement of cattle in British colonial ter- 

 ritories in Africa. H. M. Stationery Office, London. 



1955. Dairy cattle breeding in the tropics. Commonw. 



Agr. Bur. 



Mead, M. 1956. New lives for old. Gollancz, London. 



Medawar, P. B. 1956. Proc. Roy. Soc. (London), B. 



Nilsson-Ehle, H. 1909. Lunds Universitets Arskrift N.S., sec. 2, 5 (2). 



Oshima, C. 1958. J. Hered. 49:22. 



Schmalhausen, I. I. 1949. Factors of evolution. Blakiston, Philadelphia. 



Timofeeff-Ressovsky, N. W., and E. A. Timofeeff-Ressovsky. 1940. 

 Z. ind. Abst. Vererb. 79:28. 



Tschetverjkov, S. S. 1926. Zhur. Eksper. Biol. 2:3. 



Waddington, C. H. 1940. Organisers and genes. Cambridge Univ. Press, 

 Cambridge. 



1942. Nature (London) 150:563. 



1957. The strategy of the genes. Allen and Unwin, 



London, and Macmillan, New York. 



Wright, S. 1931. Genetics 16:97. 



36 



