NOTES AND LITERATURE 



RECENT LITERATURE TOUCHING THE QUESTION OF 

 SEX-DETERMINATION 



In 1889 Geddes and Thomson in their book on the "Evolution of 

 Sex" stated that "Nutrition is one of the most important factors 

 in determining sex" (p. 47), and developed the theory that 

 "Anabolic conditions favor the preponderance of females, kata- 

 bolic conditions tend to produce males" (p. 47). In the revised 

 edition of 1901 practically the same idea is stated thus: "The 

 female is the outcome and expression of relatively preponderant 

 anabolism, and the male of relatively preponderant katabolism" 

 (p. 140). The following year (1902) Beard 1 expressed the con- 

 clusion, based upon considerable evidence, that: "Any inter- 

 ference with, or alteration of, the determination of sex is abso- 

 lutely beyond human power. To hope ever to influence or 

 modify its manifestations would be not less futile and vain than 

 to imagine it possible for man to breathe the breath of life into 

 inanimate matter" (p. 763). 



The two fundamental ideas here expressed — namely, that the 

 nature of the environment (chiefly the amount of nutrition) may 

 determine the sex of the developing germ, i. e., that sex is quanti- 

 tatively determined: and that sex is predetermined in the germ, 

 i. c, qualitatively i independently of external conditions if only 

 they be favorable to development) have until recently sharply 

 divided investigators on the problems of sex. Both positions 

 seemed about equally well supported by numerous facts both 

 experimental and cytological for animals, and experimental for 

 plants. In only a few instances has opinion been divided over 

 the same form; in the majority of cases the results appeared 

 convincingly in favor of one or the other view. 



The more recent tendency seems to be to interpret sex-deter- 

 mination (at least proximately) as the result of a quantitative 

 relation between karyoplasm and cytoplasm in the fertilized 

 ovum, or more strictly, between chromatin and cytoplasm. This 

 position rests upon the observation chiefly that in those insects 

 where heterochromosomes have been described the eggs which 

 develop into females contain the greater amount of chromatin 

 material (exceptions— M< /apodi'ii*. AYilsnn : and possibly Acholla, 



i Beard, John. "The Determination of Sex in Animal Development," 



