Third Edition, Scientific Publication No. 161, prepared by Dr. A. J. Walker, consultant in Parasitology, Malaria Eradication Program (PAHO/WHO). v + 117 pages, illustrated, softbound. Pan American Health Organization, Pan American Sanitary Bureau, Regional Office of the World Health Organization, 525 Twenty-third St., N.W., Washington, D. C. 20037. 1968. No price