



EFFECTS ON THE PROTOZOA 25 



that it is due primarily, not to inanition, but to the toxic action of the bacterial 

 products in such cultures. 



In the ectoplasm, Lipska found no vacuolation (versus Chainsky) and rarely 

 any involvement of the trichocysts and cilia (versus Wallengren). The move- 

 ments become sluggish, however, and there is "un ralentissement general des 

 phenomenes vitaux." 



The macronucleus in the early stages of inanition becomes elongated and 

 slightly enlarged (Fig. 2) confirming Kasanzeff and Chainsky, staining more 

 deeply and often moving toward one end of the body. Toward the third or 

 fourth day it frequently divides into two nearly equal spheroidal masses (Fig. 

 5), which separate later, but do not undergo the granular degeneration and 

 fragmentation described by Kasanzeff, Wallengren and Chainsky (cf. Fig. 6). 



The micronucleus may leave the vicinity of the macronucleus, but (in agree- 

 ment with previous observers) usually undergoes no appreciable change in size, 

 form or structure. Although the Paramecium in normal cultures averaged 

 one division per day, only eleven cases of division were observed by Lipska in the 

 thousands of individuals during inanition. Even these few divisions may have 

 begun before inanition, as they occurred shortly after isolation. No cases of 

 conjugation were found by Lipska during inanition, special tests for this purpose 

 being made by placing five to ten paramecia together in a capillary tube. These 

 tests are admittedly inconclusive, however. 



Death of the paramecia from inanition was found to occur (as described by 

 Wallengren) either (1) slowly, by a process of gradual granular degeneration and 

 ultimate disintegration or (2) rapidly, an infrequent form due usually to a 

 mechanical injury of the (probably weakened) cell-membrane. Granular 

 masses of chromatic (nuclear) origin are frequently long recognizable in the dis- 

 integrating dead cells. 



Recovery of the starving paramecia was found possible by careful refeeding, 

 if begun not later than the third to fifth day of inanition. Division recom- 

 mences three to five days later. The process of recovery is exactly inverse to 

 the process of degeneration during inanition (confirming Wallengren). 



