SEX INHERITANCE 131 
characters peculiar to them. Within the class, 
there is great fluctuation—on the one hand to in- 
dividuals entirely male in appearance, and on the 
other to individuals nearly all of whose character- 
istics are female. An intersex of a high “female- 
type” is an individual in which most of the parts 
are purely female, a few parts are male, and others 
are mixtures. The mid-grade intersexes usually 
have rudimentary ovaries; but not infrequently 
one gonad is a rudimentary testis, or a rudimentary 
ovary with a follicle budding into a testis. The 
testes of high grade male-type intersexes are like 
those of normal males in size and appearance. All 
intersexes are sterile. The stock is maintained by 
breeding from sisters of the intersexes. Only a 
small proportion of these gives intersexes. Genetic 
tests and cytological examination show that the 
intersex-producing females are triploid (8n), pos- 
sessing three representatives of each of the four 
chromosomes. Likewise the intersexes are shown 
to be triploid for the autosomes, but only diploid 
for the X-chromosomes. Individuals with two X- 
chromosomes are not females if a third set of auto- 
somes is present; they are altered to a greater or 
less extent into males. Accordingly, the autosomes’ 
are shown to be as concerned in the production of 
sex as are the so-called sex-chromosomes. The X- 
chromosomes are seen to be chromosomes that are 
female determining in tendency, while the auto- 
somes are male determining. 
If the chromosomes determine sex by means of 
