No. 516] NOTES AND LITERATURE 



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charged to a migration of the ovum from one side to the horn of 

 the opposite side. And "in those animals such as pigs, cats, rab- 

 bits and mice — whose offspring are truly multiple — the fetuses 



are mixed up in the two cornua ; but the ovaries contain 



between them a corresponding number of corpora lutea, both 

 individually as regards sex and collectively as regards num- 

 ber" (p. 98). 



An interesting presentation is given in chapter 15 of supposed 

 reasons why more boys are born than girls. Statistics recorded 

 for over 200 years show this to be a fact, the proportion being 

 106 males to 100 females. More boys are said to be born by rea- 

 son of the greater number of male eggs liberated, and by reason 

 of easier access of spermatozoa to male ova, both due to the 

 anatomical facts above enumerated. Nature thus attempts to 

 compensate for the greater male mortality at birth and during 

 the first five years. 



Multiple conceptions are brought under the hypothesis. The 

 woman is held responsible for plural pregnancies; nevertheless 

 the author is forced to admit exceptional cases (p. 144). 



In chapter 22 Dr. Dawson attempts to analyze the more obvi- 

 ous objections to his theory. To the criticism that it is too me- 

 chanical he answers that all life is essentially mechanical, e. g., 

 respiration, circulation, menstruation. With the fact that the 

 majority of birds have only one ovary, yet the hen lays eggs of 

 both sexes, he has considerable trouble. But he makes argument 

 impossible by simply stating that woman is not analogous to the 

 hen. He seeks support for this contention by citing the fact that 

 birds are asymmetrical in other respects, i. e., absence of right 

 carotid artery and right jugular vein, adding that it is "no 

 more necessary to assume identity between birds and women in 

 the matter of the causation of sex, than in the matter of circu- 

 lation." It must be pointed out that originally (before hatch- 

 ing) both the circulatory and reproductive systems of birds are 

 identical, at least as concerns bilateral arrangement, with those 

 of the human embryo. It seems more reasonable, on the basis 

 of comparative embryology and physiology, that the human 

 ovaries have an identical, interchangeable and compensatory 

 function just as the kidneys, the testes, the eyes and the ovaries, 



The two concluding chapters deal with the problem of fore- 

 casting sex and the production of sex at will. Knowing that the 



