Series: Classics of Biology and Medicine. Translation from Ancient Greek. Introduction. article and notes by V.P. Karpov. Moscow: Biomedgiz 1937. 220 p. Hardcover. usual format. The first book is devoted to methodological issues. In the second book, Aristotle points to the elements that animals consist of, namely the beginnings of dry (bones) and wet (blood, brain, milk). thanks to which the growth and existence of the body are possible. No less necessary for the search for food are the senses. Internals (for example, heart and veins) he found exclusively in animals with blood and did not find in bloodless (for example, soft-bodied and insects). In addition to the heart, among the intestines he also considered the kidneys, liver, lungs and spleen. When classifying animals, Aristotle distinguished legless (snakes), bipeds (birds) and quadrupeds, egg-laying and viviparous, horned and hornless, multi-fingered and hoofed (single-legged and even-fingered), hairy and feathered. The appendix gives the systematics of Aristotle in the form of a table.