This book develops the idea of ​ ​ the semiotic nature of life. It follows from the theory that organisms are signs of life, and that the flesh of organisms is the substrate of the sign. From this point of view, the flesh of organisms can be studied by the same methods that are applicable to inanimate nature. This book shows that the embryonic stages of development of many animals can be considered as living crystals, and we will apply the conceptual apparatus of polyhedron geometry to their study.