146 



CYTOPLASMIC INCLUSIONS 



The demonstration that the osmiophiHc granules are an addition to 

 the simple contractile vacuoles which may exist independently of the 

 granules, even in the same species, is a close parallel to the union of 

 the progastriole and digestive granules. The only difference is that no 

 gastriole yet discovered presents a permanent, highly developed mem- 



O 





48 



O (^ 



so 



51 



Figures 48-52. Excretory granules and contractile vacuoles. Figure 48, aggregation 

 and disappearance of excretory granules during the pulsatory cycle, from Ichthyophthirius 

 multlfilih, Champyosmic impregnation (after MacLennan, 1934) ; Figures 49-50, from 

 Polyplastron tntdtivesiculatuiyi : Figure 49, cold impregnation; Figure 50, warm im- 

 pregnation (after MacLennan, 1933) ; Figure 51, from Dogielella sphaerii, Champyosmic 

 (after Nassonov, 1925) ; Figure 52, "nephridialplasm of dvnpanelLj lunbellaria, 

 Flemming-glychemalum (after Faure-Fremiet, 1925). 



brane or a permanent granular region, as in the contractile vacuoles of 

 Metadhiium , Pavamec'ium, and Haptophrya. 



The origin of a new vacuolar apparatus from the original structure of 

 the parent has been described and compared with dictyokinesis in germ 

 cells (Nassonov, 1924; von Gelei, 1928). The clearest case is that of 

 Haptophrya, in which the vacuolar apparatus is a tube extending the 

 full length of the ciliate. Studies of both live and fixed animals show 

 that this tube is permanent and that the transverse fission of the cells 



