72 



PROTOZOOLOGY 



In certain Protozoa, the chondriosomcs are not always demon- 

 strable. For example, Horning states in Monocystis the chondrio- 

 somes present throughout the asexual Hfe-cycle as rod-shaped 

 bodies, but at the beginning of the spore formation they decrease 

 in size and number, and in the spore none exists. The chondrio- 

 somcs appear as soon as the sporozoites are set free. Thus it would 

 appear that the chondriosomcs were reformed de novo. On the 

 other hand, Faure-Fremiet, the first student of the chondrio- 

 somcs in Protozoa, maintained that they reproduce by division, 







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Fig. 26. The chrondriosomes in Peranema trichophorum, X1750 (Hall)' 

 a, b, surface views and c, optical section of a single individual. 



which has since been confirmed by many observers. As a matter 

 of fact, Horning found in Opalina, the chondriosomcs are twisted 

 filamentous structures and underwent multiple longitudinal fis- 

 sion in asexual division phase. Before encystment, the chondrio- 

 somcs divide repeatedly transversely and become spherical bodies 

 which persist during encystment and in the gametes. In zygotes, 

 these spherical bodies fuse to produce longer forms which break 

 up into elongate filamentous structures. Richardson and Horning 

 further succeeded in bringing about division of the chondriosomcs 

 in Opalina by changing pH of the medium. 



As to the function of chondriosomcs, opinions vary. A number 

 of observers hold that they are concerned with the digestive 

 process. After studying the relationship between the chondrio- 



