Tremendous progress has been made in the control of many of the diseases that formerly passed from animals to man. Some, such as bovine tuberculosis and glanders, have been practically eliminated as menaces in the United States. However, diseases undergo evolution exactly as do other factors in human life. Now new chapters have become necessary on such subjects as tsutsugamushi disease, Q fever, jungle yellow fever and Haverhill fever. Moreover, what is one of the greatest outbreaks of foot and mouth disease ever to appear is now menacing cattle in Mexico and the United States It is well to have an authoritative work of this kind.