In describing the brain, he states that all red-blooded animals have that organ, as have also the mollusca, and that in man it is largest and most humid. He had observed its two membranes, as well as the hemispheres and cerebellum; but he asserts that it is bloodless, that no veins exist in it, and that it is naturally cold to the touch. He was ignorant of the distribution of the nerves, was not aware that the arteries contain blood, imagined that the heart being connected with the windpipe is inflated through it, and, in a word, manifests extreme ignorance of every thing that relates to the internal organization. Judging from this specimen, the reader may suspect that his time would not be profitably employed in separating the few particles of wheat from the great mass of chaff which the writings of Aristotle present to us. Nor must it be concealed that the modern naturalist does not consult his volumes for information, but merely to gratify curiosity. There is to be found, indeed, in the most imperfect of our elementary works on anatomy, whether human or comparative, more knowledge than was probably contained in the Alexandrian library. In his second book, he treats more particularly of animals. At its commencement we unfortunately meet with a stumbling-block, in the shape of an assertion, that the neck of the lion has no vertebrae, but consists of a single bone. In speaking of limbs, he takes occasion to describe the proboscis of the elephant, and to enter generally into the history of that gigantic quadruped. He then speaks with reference to the distribution of hair, remarking, that the hair of the human head is longer than that of any other animal; that some are covered all over with long hair, as the bear; others on the neck only, as the lion; and others only along the back of the neck, as the horse and the bonasus. He describes the buffalo and the camel; of the latter of which he mentions the two species, the Arabian and the Bactrian. The subject of claws, hoofs, and horns, is next discussed. He states that some quadrupeds have many toes, as the lion; while others have the foot divided into two, as the sheep; and others again have a single toe or hoof, as the horse. His aphorisms on the subject of horns are in general correct. Thus, he states that most creatures furnished with them have cloven hoofs, and that no single-hoofed animal has two horns.