In looking for a centre around which to arrange the almost infinite hosts of the animal kingdom, the vanity of man naturally enough suggests himself; but to gratify this vanity, he must submit to the somewhat mortifying necessity of admitting six families of apes and monkies to his immediate company, and the tribe thus constituted may be termed Primates,--a name originally conferred on it by Linnæus. Anatomy, as well as external appearances, prove the propriety of this arrangement, however repulsive the idea may be to our false feelings of exclusiveness. Primates thus constituted, will be found to be the central seventh of a larger group, termed Mammalia by Linnæus; a group, which includes all the truly viviparous and mammiferous animals. Amongst the outermost of these, as we retrograde gradually from the type, man, we shall find a bird typified in the bat; a shark in the seal; many other fish in the whale; a tortoise, crocodile, and slender lizards, in the armadillos, ant-eaters, &c., all thus exhibiting a tendency to borrow characters from other approaching groups. Mammalia, thus surrounded, must of necessity be the central of seven groups, within the compass of which will be found all animals which possess a frame of connected bones and a spinal marrow; these are termed Vertebrata, and, I think, will be found to constitute a central seventh of all animated nature. From this it will be apparent, that there are in nature forty-nine groups of animals, each of about the same value as Mammalia, as far as regards their relation to a whole. Distrustful of my own very limited knowledge of the subject, and fearful of encumbering science with crude theories and ill-defined divisions and characters which future discoveries may hereafter totally subvert, I shall content myself with observing, that I believe in the existence of such groups, and shall not presume to give them, at present, definitions or even names: the charge of ignorance is merited and easy to be borne, but the charge of attempting to establish divisions, in order to secure the paltry fame of naming them, I hope not to deserve.