262 Proceedings of the Royal Physical Society. 
that by cumulative integration, cells with preponderant cyto- 
plasm were evolved, and thus arose female cells. 
The subsequent steps in the argument are as follows :— 
“When individuals became developed in which the physio- 
logical functions of the individual were so adjusted automati- 
cally, through a correlation of those functions, as to impede 
the production of chromatin or nucleoplasm, presumably 
through the too rapid action of cumulative integration, 
cytoplasm was produced in a preponderating measure, the 
spermatogonia were hypertrophied and discharged before 
complete maturation as ova. In this way femaleness arose, 
and as “sex” thus became reflected in the physiological 
tendencies of the individuals of a species, some became male 
and others female. This carried the principle of the physio- 
logical division of labour beyond organs, and extended it to 
individuals of the same species. The female is a repressed 
male state.” 
Ryder’s interpretation of observable phenomena may be 
now summed up :— 
“Male and female sexual products were at first, and still 
continue, to be dehisced as useless products of over-assimi- 
lation, or aS a consequence of the cumulative action of 
integration.” 
Suppose an organism with a number of primitive repro- 
ductive cells. If it be a female, over-growth is diverted to 
the enlargement of the reproductive cell, to a preponderance 
of its cytoplasm, to hypertrophy. There result ova, which, 
except in the case of parthenogenesis, have lost the power to 
undergo spontaneous segmentation. These “ hypertrophied 
spermatogonia’’ may, however, give off polar bodies as “a 
phylogenetic reminiscence of the asexual or male flagellate 
state.” But if the organism be a male, the primitive repro- 
ductive cells, or spermatogonia, retain-their tendency to 
divide, in the process cytoplasm is reduced to a minimum, 
the primitive flagellate condition recurs, and, “as a conse- 
quence of the reduction of its cytoplasmic field, the male cell 
becomes incapable of further independent development.” 
“The exhaustion of the central controlling mass of nucleo- 
plasm or chromatin in the ovum, after expulsion of the polar 
