XIX.
In the way, too, of physical characteristics, common conditions develop common points of conformation. Hence, as elements of classification, physical characters are of less value than the philological moral ones.
XX.
On the other hand—as measures of the effects of common influences, physical structure and the non-philological moral elements are of more value than the phænomena of language.
XXI.
Facts requiring appreciation as influences, like those requiring appreciation as signs, are moral as well as physical. Have moral or physical causes most to do with premature nubility[194] and the want of variety in the expression of individual countenances?
XXII.
Unity of the human species.—A. protoplast is an organised individual, capable (either singly or as one of a pair) of propagating individuals; itself having been propagated by no such previous individual or pair.
XXIII.
The definition of the term species by means of the idea of descent from a single protoplast, has the advantage of being permanent and immutable; inasmuch as it is based upon a ground that no subsequent change can set aside—