426 EVOLUTION AND GENETICS 



of a circumstantial nature to support their views. Experimental 

 evidence is also abundant, but experiments have invariably given 

 inconclusive results. The idea of germinal continuity advanced 

 by Weismann has turned attention to the establishment of a 

 reciprocal connection between soma and germ plasm; this tendency 

 colors much of the literature for the Lamarckian view. In spite 

 of the fact that it competes in its unproved state with germinal 

 theories which have more or less convincing support, the idea 

 persists that acquired characters contribute to the heritage. This 

 very persistence is suggestive and valuable in that it forces us to 

 recognize that the question of evolutionary processes is still an 

 open one. 



REFERENCES 



Castle, W. E., and Philips, J. C, "On Germinal Transplantation in Verte- 

 brates," Carnegie Inst. Wash., Publication 144, 1911. 



RiGNANo, E., On the Inheritance of Acquired Characters, translated by Harvey, 

 1911. 



Child, C. M., Senescence and Rejuvenescence, 1915. 



GuYER, M. F., and Smith, E., "Studies on Cytolysins. II. Transmission of 

 Induced Eye Defects," Jorirn. Exp. Zool. XXXI, 171, 1920. 



Newman, H. H., Readings in Evolution, Genetics and Eugenics, 1921. 



Walter, H. E., Genetics, revised edition, 1923. 



CoNKLiN, E. G., Heredity and Environment, 6th edition, 1924. 



Detlefsen, J. A., "The Inheritance of Acquired Characters," Phys. Rev. V, 

 244-278, 1925. 



