Size of Nucleus 185 



regulation of size. But these facts stimulated other 

 studies. 



In starving Stentor, various nuclear transformations 

 were observed by Sosnowski ('99). The macronuclei 

 divided irregularly during such fissions as occurred, 

 so that in some individuals the nuclei were now very 

 large and in some very small. But it was not feasible 

 to estimate accurately the relative sizes. 



More reliable measurements were yielded by hun- 

 gering Paramecia when studied by Kazanzeff ('01) 

 in Hertwig's laboratory. In certain cultures the nu- 

 clei actually enlarged, as time went on, while the 

 bodies were becoming smaller, as is shown in figure 

 62. This result was substantially confirmed in this 

 species by Wallengren ('02) and Lipska ('10). Simi- 

 lar increases in the volumetric ratio of the nucleus to 

 the body were demonstrated in other species of ciliates, 

 as Dileptus (Hertwig, '02) and Colpidium (Wallen- 

 gren '02). In Ameba a like result was found by 

 Prandtl ('07), though control individuals of the same 

 culture were not studied. 



Thus far one might be quite convinced that starva- 

 tion leads to hypertrophy of nuclei, or at least to pres- 

 ervation of nuclear substance while cytoplasm disap- 

 pears. The crucial test would have been to observe the 

 return to normal relationships when food was again 

 supplied. This was never done. 



Later studies have not confirmed the above results. 

 Perhaps the diversity of fact really depends upon the 

 separation of food shortage from other influences. 

 Borowsky ('10), working in Biitschli's laboratory, ar- 

 rived at the result that hunger leads to the presence 

 of fewer and smaller nuclei in Actinosphaerium, the 

 very species upon which Hertwig's first observations 

 were made. 



The effect of progressive starvation was studied 



