On the Origin of Species by Means of Natural Selection / or the Preservation of Favoured Races in the Struggle for Life. (2nd edition)

by Charles Darwin

Types, succession of, in same areas, [339].

U.

Udders enlarged by use, [11].

——, rudimentary, [451].

Ulex, young leaves of, [439].

Umbelliferæ, outer and inner florets of, [144].

Unity of type, [206].

Use, effects of, under domestication, [11].

——, effects of, in a state of nature, [134].

Utility, how far important in the construction of each part, [199].