4 l8 TRANSMISSION 



question whether extreme development tends to affect the germ 

 and to become inherited is a question beset with many difficul- 

 ties. The greatest obstacle to this study is the ever-present 

 fact of selection, which rapidly brings about a close correspond- 

 ence between organisms and their surroundings. No reliable 

 conclusion can be drawn until this influence is accounted for 

 or eliminated. 



In further pursuance of this study we now pass to more def- 

 inite discriminations as to type and to more exact and critical 

 distinctions concerning variability as expressed not in individuals 

 but in numbers sufficiently large to be fairly indicative of the race. 



ADDITIONAL REFERENCES 



AN EXAMINATION OF WEISMANNISM. By G. J. Romanes, i vol. 

 DARWIN AND AFTER DARWIN. By G. J. Romanes. 2 vols. 

 DEVELOPMENT AND EVOLUTION. By J. M. Baldwin. Science, XVI, 



819-821. 

 ENVIRONMENT AND ITS EFFECT ON THE TRANSMITTING POWER OF 



SEEDS. By W. W. Tracy. Science, XIX, 738-740. 

 EXPERIMENTAL ZOOLOGY. By T. H. Morgan. Chapters IV and V, pp. 



43-61. 



FOUNDATIONS OF ZOOLOGY. By W. K. Brooks, i vol. 

 HEREDITY AND INSTINCT. By J. M. Baldwin. Science, III, 439-44;, 



558-559- 

 INHERITANCE OF ACQUIRED CHARACTERS. By E. D. Cope. Science, V, 



633-634 ; by John McFarland, Ibid., 935-945. 



INHERITANCE OF ACQUIRED CHARACTERS. (Examples.) By F. H. Her- 

 rick. Science, VII, 280. 



INHERITANCE OF ACQUIRED CHARACTERS. By D. E. Hutchens (1904). 

 Nature, LXXI, 83. 



NATURE OF CANCERS AND ABNORMAL GROWTHS, AND TRANSMISSIBILITY 

 OF SAME. By E. B. Bashford. Proceedings of the Royal Society, 

 London, LXXIII, 66-67. 



RIGHT- AND LEFT-EYEDNESS. By G. M. Gould. Science, XIX, 591-594. 



THE HEREDITY OF ACQUIRED CHARACTERS. Boston Medical and Surgi- 

 cal Journal, CXXXVII, 427-428. 



USE-INHERITANCE. Direction of Hair in Man and Animals and its Appli- 

 cation to Darwinism. By W. Kidd. Science, XV, 142-143; also in 

 Science, XX, 401-407. 



