A classic scientific monograph on parasitology, devoted to the study of the larvae of freshwater bivalve mollusks of the genus Anodonta (toothless). The author examines in detail the mechanisms of parasitism, the process of development of larvae and their interaction with the owners - freshwater fish. Fausek conducted a detailed study of the biological cycle of parasitic larvae, their structure, ways of attaching to the skin of fish, effects on the host body and further development to the adult form. The book presents both theoretical calculations and experimental observations. ???? The uniqueness of the publication A rare pre-revolutionary edition is an original scientific work of historical value. Illustrations - contains 8 sheets with detailed drawings, diagrams and diagrams. Interest for collectors - the book may be of interest to bibliophiles, collectors of antique literature and experts in the field of biology. Rare! Original edition 1903. Excellent copy for scientific research or private collection.