William Trager has been an avid student of parasites for over 50 years at the Rockefeller University. Around the turn of this century, parasitology enjoyed a certain vogue, inspired by colonial responsibilities of the technically ad vanced countries, and by the exciting etiological and therapeutic discoveries of Ross, Manson, Ehrlich, and others. For some decades, the Western hemi sphere's interest in animal parasites has been eclipsed by concern for bacteria and viruses as agents of transmissible disease. Only very recently, initiatives like the Tropical Disease Research programs of...