1921] CURRENT LITERATURE 409 
same time adds a very significant and far-reaching modification of present 
ideas on sex determination. 
An unexpected distribution in inheritance of known factors which are 
located on the second and third chromosomes of Drosophila was explainable 
on the assumption that the female parent of the cross was a triploid with 
respect to these chromosomes. Cytological examination proved that this 
was actually the case. This same group of flies also exhibited some remark- 
able irregularities in their sex condition. A considerable group of “inter- 
sexes” occurred, as evidenced by the secondary sex characters and the condi- 
tion of the gonads as well. This was apparently a bimodal group, some of 
intersexes being of a more “female type” and others of a more “male t 
Cytological examination of these individuals revealed that the second ae 
third chromosomes were regularly present in a triploid condition, that the 
fourth chromosome was either diploid or triploid, and that two «-chromosomes 
were regularly present (with or without a y-chromosome). The situation is 
interpreted as follows. ‘It is not the simple possession of two x-chromosomes 
that makes a female, or of one that makes a male. A preponderance of genes 
that are in the autosomes tends toward the production of male characters; 
and the net effect of genes in the x is a tendency to the production of female 
characters. The ratio of 2x72 sets autosomes produces a female, while 1x:2 
ae int 
s 
“‘superfemales,” and 1x73 sets autosomes “‘supermales.” The author has actu- 
ally identified such types, both being sterile. 
It is certain that this conception will exert a far-reaching influence upon 
the existing ideas of sex-determination. In the first place, it gives a somewhat 
more exact idea as to the elements effective in determining sex. Hitherto 
it has been thought, rather vaguely, that the x-chromosome determines sex 
either per se or by virtue of some special factor which it contains. It is inter- 
esting to realize that a number of factors may be influencing sex in one direc- 
tion or the other, and perhaps that these are identical with factors which have 
previously been known as playing another réle. A different rate of metabolism 
has commonly been associated with the two sexes; a study of the influence of 
specific factors on metabolic rate now becomes significant in this connection. 
In the second place, it furnishes an exact interpretation of intersexes on a 
chromosome basis. Hitherto intersexes have either been interpreted in very 
vague terms, or have been used as an argument against the chromosome theory 
of sex determination, or have been harmonized with the sex chromosome theory 
only by the assumption of some additional extrachromosomal influence 
(GoLpscumipt). The present conception paints a quantitative picture of sex 
