ON TYPES OF MANKIND, 81
This is the import of the word species, as it has long been understood by writers on different departments of natural history. They agree essentially as to the sense which they sp propagated to this term, though they have expressed themselves differently, according as they bare blended more or less of hypothesis with their conceptions of its meaning."
"VARIETIES," continues Prichard, "in natural history, are such diversities in individuals and their progeny as are observed to take place within the limits of species.
"PERMANENT VARIETIES are those which, having once taken place, continue to be propagated in the breed in perpetuity. The fact of their origination must be known by observation or inference, since, the proof of this fact being defective, it is more philosophical to consider characters which are perpetually inherited as specific or original. The term permanent variety would otherwise express the meaning which properly belongs to species. The properties of species are two: viz., original difference of characters, and the perpetuity of their transmission, of which only the latter can belong to permanent varieties.
"The instances are so many in which it is doubtful whether a particular tribe is to be considered as a distinct species, or only as a variety of some other tribe, that it has been found, by naturalists, convenient to have a designation applicable in either case." 23
Dr. Morton defines species simply to be "a primordial organic form."' He classes species, "according to their disparity or affinity," in the following provisional manner:—
"REMOTE SPECIES, of the same genus, are those among which hybrids are never produced.
"ALLIED SPECIES produce, inter se, an infertile offspring.
"PROXIMATE SPECIES produce, with each other, a fertile offspring."
GROUP.—Under this term we include all those proximate races, or species, which resemble each other most closely in type, and whose geographical distribution belongs to certain zoological provinces ; for example, the aboriginal American, the Mongol, the Malay, the Negro, the Polynesian groups, and so forth.
It will be seen, by comparison of our definitions, that we recognize
why no substantial difference between the terms types and species—permanence of characteristics belonging equally to both. The horse, the ass, the zebra, and the quagga, are distinct species and distinct types : and the Jew, the Teuton, the Sclavonian, the Mongol, the Austra-lian Negro, the Hottentot, &c.; and no physical causes known to have existed during our geological epoch could have transformed one of the types of species into another. A type, then, being a pristine or primordial form, all idea for common origin for any two is excluded, otherwise every landmark of natural history would be broken down.
It has been sagasciously remarked by Bodichon:—