Professor Owen, of London, has thrown the weight of his great name into the scale, and tells us that "man is the sole species of his genus, the sole representative of his order." But proving that man is not a monkey, as the professor has done in the lecture alluded to, does not prove that men are all of _one_ species, according to any definition yet received: he has made the assertion, but has assigned no scientific reasons to sustain it. No one would be more rejoiced than ourselves, to see the great talent and learning of Professor Owen brought fully to bear on this point; but, like most naturalists, he has overlooked one of the most important points in this discussion--_the monumental history of man_. Will Professor Owen or Dr. Bachman tell us wherein the lion and tiger--the dog, wolf, fox, and jackal--the fossil horse, and living species--the Siberian mammoth and the Indian elephant, differ more from each other than the white man and the negro? Are not all these regarded by naturalists as distinct species, and yet who pretends to be able to distinguish the skeleton of one from the other by specific characters? The examples just cited, of living species, have been decided upon simply from their permanency of type, as derived from their history; and we say that, by the same process of reasoning, the races of men depicted on the monuments of Egypt, five thousand years ago, and which have maintained their types through all time and all climates since, are _distinct species_. Dr. Morton defines species--"a primordial organic form," and determines these forms by their permanence through all human records; and Mr. Agassiz, who adopts this definition, adds: "Species are thus distinct forms of organic life, the origin of which is lost in the primitive establishment of the state of things now existing; and varieties are such modification of the species as may return to the typical form under temporary influences." Dr. Bachman objects very strongly to this definition, and declares it a "cunning device, and, to all intents, an _ex post facto_ law," suddenly conjured up during a controversy, to avoid the difficulties of the case; but we have serious doubts whether these gentlemen are capable of such subterfuge in matters of science, and confess that we cannot see any substantial difference between their definition and those given by Dr. Bachman. Morton and Agassiz determine a form to be "_primordial_" by its permanency, as proved by history, and the other definitions assign no other test. Professor Leidy, who has not only studied the "lower departments of zoology," like Mr. Agassiz, but also the "higher forms of animal life," says that "too much importance has been attached to the term species," and gives the following definition: "A species of plant or animal may be defined to be an immutable organic form, whose characteristic distinctions may always be recognized by _a study of its history_."[199]