. The biology of the protozoa. Protozoa; Protozoa. Fig. 218.—Type of Hemogregarines. A, Haemogregarina stepanowi; B and C, Lankesterella ranarum. (Original.) Class II. CNIDOSPORIDIA Doflein. The Cnidosporidia form an independent stem of the Protozoa with no recognizable affinities with other groups. They are ame- boid and, in the adult stage, usually multinucleated, thus resembling the Mycetozoa. Encapsulated sporoblasts and general mode of life as parasites show some resemblance to the Telosporidia but the life cycle is less complicated, sexual dimorphism and change of hosts being absent. Unl
. The biology of the protozoa. Protozoa; Protozoa. Fig. 218.—Type of Hemogregarines. A, Haemogregarina stepanowi; B and C, Lankesterella ranarum. (Original.) Class II. CNIDOSPORIDIA Doflein. The Cnidosporidia form an independent stem of the Protozoa with no recognizable affinities with other groups. They are ame- boid and, in the adult stage, usually multinucleated, thus resembling the Mycetozoa. Encapsulated sporoblasts and general mode of life as parasites show some resemblance to the Telosporidia but the life cycle is less complicated, sexual dimorphism and change of hosts being absent. Unlike the Telosporidia reproduction does not bring the life of an individual to an end but takes place more or less continuously throughout the trophic stages, the sporoblasts being carried about with the more or less active organism which ultimately may become a relatively huge mass of spores. Sporulation and sexual processes are entirely different from analogous activities in the Telosporidia. In a typical form of Myxosporidia in which the ameboid body is multinucleated and the nuclei frequently dimorphic, sporulation begins with a peculiar process of internal budding. An island of protoplasm is formed about two of the nuclei, one of each kind if dimorphic, and this island was termed a pansporoblast by Gurley. This gives rise to two cells, each with 7 nuclei after the 2 nuclei have divided to form 14 nuclei which are now all alike. Two of these 7 nuclei disappear with the formation of a bivalved capsule, 2 of them disappear with the formation of peculiar nematocyst-like capsules termed 35. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Calkins, Gary N. (Gary Nathan), b. 1869. Philadelphia, Lea & Febiger
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