Twenty years ago it was an amusing pastime to see with the aid of the microscope, and to describe, new and interesting forms of unicellular organisms. Today there is not a field of biological science that is not illumined by the deeper study of the protozoa, and the pastime of our fathers has become the science of protozo ology to-day. In its modern aspect this new science has many sides, morphology, physiology, psychology, cytology, and pa thology, and although there is little danger of its being cut up into unrecognizable parts, there is need of some ground principle or principles to hold the many branches of protozoa study together and to unify the science. It was the genius of Schaudinn, whose untimely death has taken from protozoA¶logy its most brilliant light, to establish such an unifying foundation, and in his clear perception of the importance of the life cycle we have the key note of our present day conception of the protozoa. With our present knowledge we may define protozoa as: Independent, uni cellular, animal organisms which reproduce by division or spore formation, the progeny passing through various phases of activity collectively known as the life cycle, and manifesting various degrees of vitality with accompanying form changes. In thus emphasizing the life cycle in the definition I would seek to introduce into protozoa study the recognition of the entire cycle of changes as a necessary basis for species. I would have the presentation of the life history of a protozoA¶n a prerequisite for its acceptance as a new species and would have zoologists recog
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Nov 1, 1960
Open Access
Phillip R Fordyce 