OLOGY, COMPARATIVE, and kindred articles. Animal psychology and behaviour, which has also received much attention recently, is covered by the general articles COMPARATIVE PSYCHOLOGY and ANIMAL BEHAVIOUR, while COURTSHIP OF ANIMALS, PLAY IN ANIMALS, EDUCATION IN ANIMALS and other articles deal with special points. Such important groups as PROTOZOA and TAPEWORMS are treated at length and their relations to man clearly brought out, while much of the information is summarized and its main bearings pointed out in the articles PARASITOLOGY and PARASITISM. Finally the application of biological knowledge to man's problems is considered in such articles as MARINE BI