FECUNDATION. 345 



The Urst question which naturally arises, and which has 

 engaged the attention of ancient as well as modern authors, 

 relates to the conditions which determine the sex of the off- 

 spring. The older writers, whose exact physiological knowl- 

 edge was comparatively limited, were able to present explana- 

 tions of some of the phenomena of generation, which were 

 more or less satisfactory in their day ; but many of these have 

 been contradicted by more recent facts, which have only ren- 

 dered the causes of the phenomena more obscure. Iconoclasm 

 in physiology is almost a" necessary consequence of the acqui- 

 sition of deiinite knowledge ; and too often the exact student 

 must fail to substitute any thing to supply the places of the 

 broken images of antiquity. This is illustrated in the ques- 

 tion of the determination of the sex of offspring. Statis- 

 tics show clearly enough the proportions between male and 

 female births ; but nothing has ever been done in the way 

 of procreating male or female children at will. According 

 to Longet, the proportion of male to female births is about 

 104 to 105, 1 these figures presenting certain modifications 

 under varying conditions of climate, season, nutrition, etc. ; 

 Girou de Buzareingues has shown, by very extensive observa- 

 tions upon certain of the inferior animals, that the prepon- 

 derance of sex in births bears a certain degree of relation to 

 the vigor and age of the parents ; and that old and feeble 

 females fecundated by young and vigorous males bring forth 

 a greater number of males, and vice versa ; 2 but no exact 

 laws of this kind have been found applicable to the human 

 subject. The idea that one testicle produces males and the 

 other, females, or that the two ovaries have distinct func- 

 tions in this regard, has no foundation in fact ; for men with 

 one testicle, or females with a single ovary, produce offspring 

 of both sexes. 3 



1 LOXGET, Traite de physiologic, Paris, 1869, tome iii., p. 821. 



2 GIROU DE BUZAREINGUES, Reproduction des animaux dotnestiques. Journal 

 de physiologie, Paris, 1827, tome vii., pp. 127, 132 ; Idem., 1828, tome viii., p. 

 10 ; De la generation, Paris, 1828, p. 133, et seq. 



3 A very interesting case bearing upon the question under consideration has 



