122 



PROTOPLASMIC AGE OF PROTOZOA 



to Kuschakewitsch ('07), the gametic nuclei, are formed by nuclear 

 fragmentation. 



A slight modification of this method of idiochromidia formation is 

 found in Ameba proteus, where, according to Calkins ('07), the primary 

 nucleus divides repeatedly until about seventy nuclei are present in the 

 cell. These primary nuclei then give rise to secondary nuclei, which 

 form from the chromatin granules inside of the primary nuclei. The 

 chromatin substance of the primary nuclei is thus metamorphosed into 

 secondary gametic nuclei, and these conjugate two by two. Here the 

 process may be interpreted as a precocious development of the gametic 

 nuclei, a development taking place before the primary ones are com- 

 pletely fragmented (Fig. 53). 



Fig. 51 



Ameba Umax. Aggregations of idiochromidia to form sixteen secondary nuclei, which 



then unite to form eiglit. 



The vegetative distributed chromatin granules or true chromidia, 

 as seen in Actinospherium eichhomii are formed by similar nuclear 

 fragmentation; it is quite obvious, therefore, that the method of 

 formation of these distributed chromatin granules has little or nothing 

 to do with the subsequent function. 



(6) The Significance of Idiochromidia. — It is quite apparent 

 from even the few cases cited above that we cannot generalize as to the 

 function of the deeply staining granules of nuclear origin in the cyto- 

 plasm of protozoa. In some cases (e. g., actinospherium, ophryo- 

 cystis, caryotropha, etc.), whatever may be their significance in the 



