Note (return) — ORGANIC DIFFERENCES IN THE SEXES

These facts are not conclusive, but they all point in the same direction, and are probably sufficient to establish a connection between food conditions and the determination of sex. But behind the mere fact that a different attitude toward food determines difference of sex lies the more fundamental—indeed, the real—explanation of the fact, and this chemists and physiologists are not at present able to give us. Researches must be carried farther on the effect of temperature, light, and water on variation, before we may hope to reach a positive conclusion. We can only assume that the chemical constitution of the organism at a given moment conditions the sex of the offspring, and is itself conditioned by various factors—light, heat, water, electricity, etc.—and that food is one of these variables.15 It is sufficient for our present purpose that sex is a constitutional matter, indirectly dependent upon food conditions; that the female is the result of a surplus of nutrition; and that the relation reported among the lower forms persists in the human species.