Note F — Chapter III · REPRODUCTION AND DEVELOPMENT.

Professor Geddes and Mr. J. Arthur Thomson, in their interesting work on "The Evolution of Sex," regard the ovum in especial, and the female in general, as preponderatingly anabolic (see note, p. 32); while the sperm in especial, and the male in general, are on their view preponderatingly katabolic. Regarding, as I do, the food-yolk as a katabolic product, I cannot altogether follow them. The differentiation seems to me to have taken place along divergent lines of katabolism. In the ovum, katabolism has given rise to storage products; in the sperm, to motor activities associated with a tendency to fission. The contrast is not between anabolic and katabolic tendencies, but between storage katabolism and motor katabolism. Nor do I think that "the essentially katabolic male-cell brings to the ovum a supply of characteristic waste products, or katastates, which stimulate the latter to division" (l.c., p. 162). I believe that it brings an inherited tendency to fission, and thus reintroduces into the fertilized ovum the tendency which, as ovum, it had renounced in favour of storage katabolism.