238 BIOLOGY OF THE PROTOZOA 



formation of specialized structures of the fruiting bodies (elaters, 

 etc., Kranzlin, 1907); others divide by mitosis to form nuclei of the 

 spores contained with the elaters in the spaces of a meshwork formed 

 by a special protective and supporting part of the fruiting bodies 

 called the capillitium (Fig. 184, p. 447, see also p. 44(i). 



Multiple division in the Sporozoa is characteristic of practically 

 all Coccidiomorpha, particularly in agamogony. The nuclei divide 

 repeatedly by mitosis until many are formed, after which the body 

 plasm breaks up into as many agametes as there are nuclei. In 

 many cases a portion of the old cells is left unused or not included 

 in the protoplasm of the offspring. Thus in Plasmodium vivax 

 and other malaria organisms, the pigmented granules (melanin) are 

 left behind when the agametes separate (Fig. 124) ; in many coccidia 

 the agametes are oriented in respect to such residual products. 

 Multiple division is also characteristic of the developing zygotes of 

 gregarines and hemamebidae, the eight sporozoites of gregarines 

 and the multitude of Sporozoites of Plasmodium being formed in 

 this manner. 



A B C 



Fig. 124. — Malaria organisms. .4, Plasmodium vivax in blood corpuscle; B, same 

 in agamete formation with distributed melanin (m). C, Plasmodium ?nalariae, 

 agamete formation with concentrated melanin, c, red blood corpuscle; m, melanin; 

 n, nuclei; /), parasite; v, vacuole. (After Calkins.) 



In the above account of the reproductive activities of the Protozoa 

 no attempt has been made to give an exhaustive treatment, but 

 other examples will be given in the following chapters on classi- 

 fication. 



In many cases in the above description there is evidence of 

 reorganization of the protoplasm and evidence that may be inter- 

 preted as supporting Child's view of de-differentiation as an offset 

 to the accumulation of products of metabolism which hamper 

 further metabolic activities. Some of this evidence is given 

 in connection with the phenomena of equal division, particularly 

 in division of the ciliated forms and the conclusions reached are 

 in agreement with Child's. Hartmann, also, comes to a similar 



