SEX DETERMINATION — A SUGGESTION. 13 



combinations of chromosomes, behaving as though non- 

 disjunction takes place independently in each set of three. 

 Amongst the offspring of a triploid female (mated to a normal 

 male) there is one class that has three II's, three Ill's, and 

 three IV's, but with two X chromosomes. This individual 

 is an inter-sex, more like a male than a female. There is 

 another class that has three II's, three Ill's, but only 

 two IV's. It also is an inter-sex, but more like a 

 female." Here is an abnormality of sex associated with an 

 abnormal distribution of autosomes. Morgan concludes, 

 " Thus sex itself, in this animal, is shown to be an expression 

 of a balance between the X chromosomes and the rest of the 

 chromosomes. The results show that the differentials which 

 determine sex are not confined to the sex-chromosomes alone. 

 Some appear to be in the II- and Ill-chromosomes, and others 

 in the IV-chromosome." 



I would suggest that there are no sex determinants at 

 all in any chromosomes, but that sex is the expression of the 

 total metabolism of a cell and is as fundamental a property 

 of protoplasm as life itself ; and that being an alternating 

 phenomenon it carries with it the chromosome distribution in 

 some such way as is outlined above. 



References. 



1. Doncaster, L. Journ. of Genetics, Vol. Ill, p. 11. \ l .)V.\ 



■2. Pearl, I!., an. I Pabshlby, H. M. Biol. Bull., Vol. XXIV, NTo. 1. 



I». 205. 1913. 



:*. Riddle, 0. Amer. Nat., Vol. I., p. 'Mr,. L916. 



4. Earrison, J. W. II. Journ. <>1 Genetics, Vol. IX. p. I. I!)l!>. 



5. Gold80HMIDT, R. Amer. Nat., Vol. L, p. 705. li'hi. (Brief 

 account in English, with full references). See also 7. 



I). DONCASTER, l>. Papei t'> appear in AugUSl nunilxT of Quart. 

 Journ. <>f Mic. 8ci. L922. 



7. Goldschmidt, R. " Mechanismus und Physiologie der Gesoh- 

 techtsbestimmung." Berlin, 1920. See also .">. 



