[87]

Oct 12th

Lupinus polyphyllus

(Used)

57 62

[slip of paper pasted on:]

Chap. 8

through sexual selection cannot fail to be complex in the highest to an extreme by the highest degree.

 

(When variations occur rather late in life in one sex, & are transmitted to the same sex at the same age, the other sex & the young are necessarily left unmodified. When they occur late in life, but are transmitted to both sexes, the young alone will be are are left unmodified. But Variations, however may occur early in life in one sex or in both, & be transmitted to both sexes at all ages, & then all the individuals of the same species will be similarly modified. It appears, as we shall see in the following chapters, that all these several causes are all met with under nature.)

Sexual selection can never act on any [words excised] before the age for reproduction has arrived; & it generally acts

[Descent, pp. 296-7: "Sexual selection will also be dominated by natural selection for the general welfare of the species. Hence the manner in which the individuals of either sex or of both sexes are affected through sexual selection cannot fail to be complex in the highest degree.
When variations occur late in life in one sex, and are transmitted to the same sex at the same age, the other sex and the young are necessarily left unmodified. When they occur late in life, but are transmitted to both sexes at the same age, the young alone are left unmodified. Variations, however, may occur at any period of life in one sex or in both, and be transmitted to both sexes at all ages, and then all the individuals of the species will be similarly modified. In the following chapters it will be seen that all these cases frequently occur under nature.
Sexual selection can never act on any animal whilst young, before the age for reproduction has arrived."]