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TEE AMERICAN NATURALIST [Vol.XLIV 



Payne), and has been suggested as probable more particularly by 

 Morgan and by Wilson. The former, 2 however, regards the 

 quantitative interpretation of sex-determination as only the 

 "first rough approximation" (p. 348) to the solution; and the 

 latter 3 inclines to the belief that "if the idiochromosomes be sex- 

 determinants their difference is probably a qualitative one" (p. 

 189), though this may possibly be a difference merely of degree 

 of special activity. 



Boveri's* generalization that the cytoplasm and nucleoplasm 

 of cells bear to each other a constant ratio, and that "a ferti- 

 lized egg that contains more chromatin is a potentially larger 

 cell than one with less chromatin" (pp. 9-10) may help to recon- 

 cile the conflicting theories. If the amount of chromatin may 

 be rightly taken as an index of the state of nutrition or poten- 

 tial anabolic capacity, the apparently contradictory facts that 

 nutrition (environment) in one case and internal factors (per- 

 haps simply more or possibly more active chromatin) in the 

 other case determine sex, can be harmonized. If chromatin and 

 chromatic substances (nucleo-proteids) may be regarded as food 

 material or active agents in constructive metabolism, the better 

 nourished gametes (or such as contain more chromatin) appear 

 destined to produce the female sex, the less well nourished the 



Several recent invesl i<_r;it nms ji^nin nl'tirm the opposing views, 

 well supported with experimental or cytological facts, though a 

 reconciliation is suggested from both sides on the basis of a 

 quantitative relationship signifying in one direction high metab- 

 olism (anabolism) and in the other low metabolism ("relatively 

 preponderant katabolism"). 



The most important recent paper concerning the question of 

 the determination of sex is that of Russo. 5 This author takes 

 issue with the prevailing: hypothesis which views the chromo- 

 somes as the vehicles of the determinants of hereditary charac- 

 ters, and objects more especially to a Mendelian interpretation of 



2 Morgan, T. H., "A Biological and Cytological Study of Sex Deter- 

 mination in Phylloxerans and Aphids," Journ. Exp. Zobl., Vol. 7, no. 

 2, 1909. 



8 Wilson, E. B., "Studies on Chromosomes, V." Journ. Exp. Zobl., 

 Vol. 6, no. 2, 1909. 



4Boveri, Th., "Ueber Beziehungen des Chromatins zur Geschlechts- 

 Bestimmung," Sits. Phys. med. Gesell. Wurtzburg., Jahrgang 1908-1909. 



BEusso, A., "Studien ueber die Bestimmung des weiblichen Gesch- 



