This is a readable survey of an enormous amount of literature on the infectious diseases which may be related to pathologic conditions of the human nervous system. The book is particularly valuable as an aid to the investigator. Although it is by no means a complete textbook on bacteriology, it has covered many fields not dealt with in texts, particularly the investigation on the bacteriology of the so-called functional nervous diseases. There are eight chapters on the possible relationship of infection to the functional psychosis and to epilepsy. Combing the literature and offering the results of his own work in this field, the author discounts focal infection, autointoxication and "filterable forms of tuberculosis" as being of primary importance in such conditions; also, he finds that the body fluids of psychotic patients do not differ substantially from those of normal persons. There are four interesting chapters on allergy and hypersensitiveness.