THE HJIMOFLAGELLATES. 231 



or from the degeneration of more or less typical agglomeration rosettes. 

 In the latter case the individuals fuse up into a common mass. The process 

 hegins in the centre and gradually extends to the periphery, the Trypano- 

 somes losing their independence and distinctness (fig. 22 l). Thus are 

 formed large plasmodial masses (so-called "plasmodia") consisting of great 

 numbers of nuclei embedded in a now more or less hyaline cytoplasmic 

 matrix (fig. 21s). 



If the organisms remain subjected to the unfavourable influences, or if 

 involution has reached too advanced a stage, death and disintegration result. 

 The cytoplasm is the first to disappear, becoming hyaline and colourless, and 

 refusing to stain up (q, r). The nucleus rapidly follows suit. The most 

 resistant elements are the kinetonucleus and flagellum, which may persist 

 long after other traces of the organism have vanished (p), the former as 

 a little thickening at one extremity of the latter ; sometimes the flagellum 

 alone is left. 



(To he continued.) 



