1887] The Significance of Sex. 25 
Then on the physiological side, there is a vast and fruitful field 
both of accumulated facts and promising experiments for future 
research. The numerical relations of the sexes under fluctuating 
conditions so comprehensively discussed by Diising in his memoir 
‘on the “ Regulation of the Sexual Ratio,” first invite our con- 
sideration. Next we cannot escape a discussion of the problem 
of Heredity, because this is the very soul and centre of all these 
other problems; and finally we must necessarily conclude by 
discussing the doctrine of the Genesis of Species. 
We thus see that this inquiry is one of vast proportions, and 
can understand why it is still unsettled, in spite of the flood of 
speculations that all ages have poured upon it because of its ab- 
sorbing interest and importance. But all except a very few of 
these attempts at a solution of the problem of sex are of no - 
scientific and only of slight historic value. We shall only attempt 
a summary of our present knowledge of the subject as a founda- 
tion for future progress. 
The stimulus this kind of research received through the 
labors of Darwin has not been effected in as great a degree among 
English-speaking savants as with the Germans. It is desirable 
that more interest in this subject be awakened among American 
naturalists, not alone for the sake of national pride, but also be- 
cause the obscure recesses of this great problem can be illumi- 
‘nated only by the combined labors of many minds. 
The earliest thinkers, acquainted only with the highest forms 
of life, naturally supposed that the interaction of the two sexes 
was necessary to produce a new being. Some, as Hippocrates 
and Galen, supposed that the two parents contributed equally 
and in a complementary manner to this achievement ; others, as 
Aristotle, Fabricius, Harvey, thought that one parent was sub- — 
ordinate in his influence, being a mere stimulus to development: 
The discovery of the ovum and spermatozoon gave more definite- 
ness to these theories, and so arose the schools of the ovulists, 
who saw in the spermatozoon a fertilizing element of the ovum, 
and the spermatists, who thought the ovum or the uterus to be a 
nidus where the spermatozoon was nourished and developed to 
the new being. Advancing knowledge dispelled the latter views 
and modified the former, but now arose the controversy of evolu- 
‘ftom vs. epigenesis, and so for a season attention was diverted from 
_ the main problem of the significance of sex. 
