Theognis, selection in mankind.

Theridion, stridulation of males of.

Theridion lineatum.

Thomisus citreus, and Thomisus floricolens, difference of colour in the sexes of.

Thompson, J.H., on the battles of sperm-whales.

Thompson, W., on the colouring of the male char during the breeding season; on the pugnacity of the males of Gallinula chloropus; on the finding of new mates by magpies; on the finding of new mates by Peregrine falcons.

Thorax, processes of, in male beetles.

Thorell, T., on the proportion of sexes in spiders.

Thornback, difference in the teeth of the two sexes of the.

Thoughts, control of.