From this I conclude, whether there be many or few genera in an order, the number of species in a genus is not much affected; but perhaps when [there is] only one genus in an order it will be affected, and this will depend whether the [genus] Erythroxylon be made a family of.英文原著 · 《More Letters of Charles Darwin Volume I》
But how are the five genera to be regarded? Do they form particulars by being broken up into parts? No; the genus exists as a whole in each of the things whose genus it is. But how, at that, can it remain a unity? The unity of a genus must be considered as a whole-in-many. Does it exist then only in the things participating in it? No; it has an independent existence of its own as well. But this will, no doubt, become clearer as we proceed.英文原著 · 《THE SIX ENNEADS》
(6) When the difference between the patterns of the model and presumed ancestor of the mimic is very great, the female is often alone mimetic; when the difference is comparatively small, both sexes are commonly mimetic. The Nymphaline genus Hypolimnas is a good example. In Hypolimnas itself the females mimic Danainae with patterns very different from those preserved by the non-mimetic males: in the sub-genus Euralia, both sexes resemble the black and white Ethiopian Danaines with patterns not very dissimilar from that which we infer to have existed in the non-mimetic ancestor.英文原著 · 《Darwin and Modern Science》
Can you think of cases in any one species in genus, or genus in family, with certain parts extra developed, and some adjoining parts reduced? In varieties of the same species double flowers and large fruits seem something of this--want of pollen and of seeds balancing with the increased number of petals and development of fruit. I hope we shall see you here this autumn.英文原著 · 《More Letters of Charles Darwin Volume I》
It is a very curious thing that the Azores do not contain the (non-European) American genus Clethra, that is found in Madeira and Canaries, and that the Azores contain no trace of American element (beyond what is common to Madeira), except a species of Sanicula, a genus with hooked bristles to the small seed-vessels. The European Sanicula roams from Norway to Madeira, Canaries, Cape Verde, Cameroons, Cape of Good Hope, and from Britain to Japan, and also is, I think, in N. America; but does not occur in the Azores, where it is replaced by one that is of a decidedly American type.英文原著 · 《More Letters of Charles Darwin Volume I》
A genus!--a man who can do everything in life except anything that's useful--that's a genus.英文原著 · 《The Lady of Lyons》