variations in the same parts having been accumulated by natural and sexual selection, and thus having been adapted for secondary sexual, and for ordinary purposes.

10. Distinct Species Present Analogous Variations, So That A Variety Of One Species Often Assumes A Character Proper To An Allied Species, Or Reverts To Some Of The Characters Of An Early Progenitor

These propositions will be most readily understood by looking to our domestic races. The most distinct breeds of the pigeon, in countries widely apart, present sub-varieties with reversed feathers on the head, and with feathers on the feet, characters not possessed by the aboriginal rock-pigeon; these then are analogous variations in two or more distinct races. The frequent presence of fourteen or even sixteen tail-feathers in the