Influence of Environment upon the Organism. 479 



response to diiferent environment. Many species are 

 only adaptive modifications. Their virulence for one 

 plant may be attenuated by prolonged culture on another. 



78. PviTZEMA-Bos, T. Futteranderimg bei Iiisckten. Biol. Cen- 



tralblt., vii. (1887), pp. 321-331. 



79. DusiNG, K. Die Faktoren welcbe die Sexualitat entscheiden. 



Jen. Zeitschr. f. Naturw., xvi. (1883), pp. 428-464. 



Influence of nutrition on reproduction, and on the sex of the 

 progeny. 



80. . Die Eegulirung des Gescblechtsverhaltnisses 



bei der Yermehrung der Menscben, Thiere, und 

 Pflanzen. Jen. Zeitscbr. Naturw., xviii. (1884), jip. 

 593-940, also sep. 



81. . Die experimentelle Priifung der Tbeorie von 



der Regiilirung des Geschlecbtsverbaltnisses. Jen. 

 Zeitscbr. Naturw., xiv., Suppt. (1885), p. 108. 



82. Gaule, J. Bedeutung der Cytozoen. Biol. Centralblt., vi. 



(1886), pp. 345-351. 



Influence of fasting periods on reproductive organs, in frog, 

 and in salmon (Miescher). 



83. Geddes, p. Art. Sex. Encycl. Brit., xxi., pp. 720-724. 



Gives authorities for influence of nutrition on sex of insect 

 larvae, tadpoles (Yung, E. ), etc. The better nutrition 

 the higher percentage of female forms. 



84. . Theory of Growth, Keproduction, Sex, and 



Heredity. P. K. Soc. Edin., 1886, pp. 911-931. 



"In determination of sex influences inducing katabolisra 

 (deficient nutrition, etc.) tend to result in production 

 of males, as those favouring anabolism similarly to in- 

 crease the probability of females." 



85. Grawitz, p. Beitrage zur systematiscben Botanik der 

 pflanzlicben Parasiten, und .experimentelle Unter- 

 sucbungen liber die durcb sie bedingten Krankbeiten. 

 Vircbow's Arcbiv, Ixx. (1877), pp. 546-598. 



Cited by Krukenberg, an instance of the experimental modi- 

 fication of a funffus. 



