THE DETERMINATION OF SEX. 5 1 



temperature, shorter life, Sue. ; and that the females were the 

 larger, more passive, vegetative, and conservative forms. 

 Theories of " inherent " maleness or femaleness were rejected, 

 since practically merely verbal ; more accurately, however, 

 they have been interpreted and replaced by a more material 

 conception, which finds the bias of the whole life, the 

 resultant of its total activities, to be a predominance of the 

 protoplasmic processes either on the side of disruption or 

 construction. This conclusion has still to receive cumulative 

 proof, but one large piece of evidence is now forthcoming, that, 

 namely, of the present chapter. If influences favouring kata- 

 bolism make for the production of males, and if anabolic 

 conditions favour females, then w^e are strengthened in our 

 previous conclusion, that the male is the outcome of pre- 

 dominant katabolism, and the female of equally emphatic 

 anabolism. 



§ 6. Weis?fiafi?i''s Theory of Heredity. — In thinking of the 

 environment as a factor determining the sex, it is impossible to 

 ignore that such facts as we have noted above have some 

 bearing upon the problem of heredity. Much of the recent 

 progress in the elucidation of the facts of inheritance has been 

 due to Weismann, who, in his theory of ihe continuity of the 

 germ-plasma, has restated the very important and fundamental 

 conception of a continuity between the reproductive elements 

 of one generation and those of the next. To this restatement 

 we shall afterwards have to refer ; it is with another position, 

 not peculiar to, but emphasized by the same authority, that we 

 have here to do, viz., with his denial of the inheritance of 

 individually acquired characters. Any new character exhibited 

 by an organism may arise in one of two ways, w^hich it is easy 

 enough to distinguish theoretically ; — it may be an outcrop of 

 some property inherent in the fertilised egg-cell, that is, it may 

 have a constitutional or germinal origin ; but, on the other 

 hand, it may be impressed upon the individual organism by the 

 environment, or acquired in the course of its functioning, that 

 is, it may have a functional or environmental origin. Thus an 

 increase of calcareous matter in an animal might well be wholly 

 of constitutional origin ; but a change to a new diet, or to a new 

 medium, might be followed by modifications arising, in one 

 sense, from without. But all such functional and environ- 

 mental variations are, according to Weismann, restricted to the 

 individual organism ; they are not transmissible. 



