190 DYNAMICS OF LIVING MATTER 



A good deal of mysticism arose from the fact that the number of 

 young males and females is so approximately equal in many forms, 

 e.g. in the human race. The fact, discovered by McClung, that through 

 the process of chromosome division two kinds of sex cells must be 

 formed in equal numbers in the male of Hemiptera and Orthoptera 

 removes this source of mysticism. 



The fact that all attempts to influence the sex of a developing embryo 

 have thus far failed, harmonizes with the data given above. Born and 

 others maintained that it was possible to influence the sex of tadpoles 

 or frogs, or of the larvae of flies, by the food on which the larvae were 

 fed. These statements have proved to be untenable. 



Maupas and Nussbaum have tried to determine sex, not by any 

 influence upon the developing embryo directly, but upon its offspring. 

 They experimented on a Rotifer, Hydatina senta. Nussbaum states 

 that the mode of nutrition of the female embryo after it leaves the egg 

 determines whether it will later give rise to large female eggs, or to 

 small eggs for both sexes. Maupas had stated that the temperature 

 determines the sex; but Nussbaum disagrees with him, believing that 

 temperature has no direct effect upon the determination of sex.* 



The two sexes differ also in regard to the so-called secondary sex- 

 ual characters, e.g. the shape of the antennas in male and female 

 butterflies, etc. The question now arises, Are these secondary char- 

 acters already predetermined in the egg, or are they secondarily 

 determined by the maturing or mature sexual glands? If the former 

 were the case, the castration of the larvae before sexual maturity is 

 reached should not prevent the development of the secondary sexual 

 characteristics. Oudemans extirpated the sexual glands in caterpillars 

 of Ocneria dispar, yet the butterfly showed all the secondary sexual 

 characters. Professor Kellogg told me that he found that the castra- 

 tion of the young caterpillars of the silkworms has no effect upon the 

 formation of the secondary sexual characters. These observations 

 also agree with the idea that the secondary sexual characters are pre- 

 determined in the egg, and some of them possibly at as early a stage 

 as the primary sexual characters. 



The idea that the sexual glands determine, e.g. by internal secretion, 



to instincts, man and woman represent different species, and inasmuch as for a normal 

 and happy life the instincts must act as a guide, it would seem erroneous to attempt to 

 make life for both sexes absolutely identical. It would be equally preposterous, however, 

 to insist that, for this reason, man and woman should not have equal rights. The traditional 

 barriers to the rights of women are based, not on physiological grounds, but on the survival 

 of the savage's idea, who made woman his slave. The adjustment of the sphere of action 

 of woman should be left to her own instincts and judgment, and not to the dictation of 

 lawyers and politicians. 



* For further information, see Herbst, Formative Reize in der thierischen Ontogenese, 

 Leipzig, 1901. 



