190 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
II. Sex an Attribute of each Gamete, and Hereditary. 
The last forty years have seen the rise, culmination, and at least 
incipient decline of a plausible but fundamentally erroneous idea about 
sex, — the idea that it is subject to control through the environment of 
the developing organism. ~The latest manifestation of this idea is found 
in Schenk’s (:02, :02* ) theory of sex-control in man through regulation 
of the nutrition of the mother. One or the other, or both, of two fal- 
lacies are involved in all such theories of sex-control. (1) It is known 
that in animals which reproduce sometimes by parthenogenesis, some- 
times by fertilized eggs, good nutrition favors the former process, poor 
nutrition the latter. But in the former process, when it proceeds with- 
out interruption, the offspring ave all of the female sex, whereas the 
first effect of poor nutrition is the production of males, and this is fol- 
lowed by the production of fertilized eggs. The conclusion is drawn 
that good nutrition favors the production of females among animals gen- 
erally, and that poor nutrition results im general in the production of 
males. As a matter of fact the primary effect of good nutrition, in the 
ease described, is not female production, but parthenogenesis, and the 
effect of poor nutrition is, not primarily male production, but reproduction 
by fertilized eggs, in which process the production of males is necessarily 
involved. The determination of parthenogenesis instead of sexual re- 
production is one thing, determination of sex in animals not  parthe- 
nogenetic is quite another thing. (2) The other fallacy mentioned 
relates solely to the case of animals not parthenogenetic. Its true 
nature has been repeatedly pointed out, but apparently none too often, 
for Schenk seems to rest his theory-upon it. Feeding experiments, 
especially with Lepidoptera, often lead to the production of an excess of 
males when the nutrition is scanty, simply because the female requires 
a greater amount of food to complete her development. Excess of males 
because of a greater mortality among female individuals is wrongly 
interpreted as a production of male individuals by a scanty diet. 
On the other hand, evidence has been steadily accumulating in recent 
years to show that sex is inherent in the germ, and is not subject to 
control in the slightest degree by environment. A masterly summary 
of this evidence has been made in the case of animals by Cuénot (’99), 
and in the case of plants by Strasburger (:00). 
If it be true that sex is inherent in the germ, and is independent of | 
environment, it must be contained in one or the other or both of the 
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