Inheritance of Size 



55 



to one clone. After isolating individuals from various 

 sources, the descendants of each were found to be not 

 only closely similar in size among themselves, but also 

 highly diverse from the other clones. Moreover, as 

 changes of environment resulted from variations in 



30 



60 



90 120 



Time in days 



150 



880 



910 



Figure 24. Inheritance of body length in various clones of Paramecium. 

 The individuals which were fixed and measured grew in mass cultures. 

 Each point represents the mean length for many individuals killed at one 

 time. The synchronous upward and downward trends are due to variations 

 in the environmental conditions. Clones V and D were Paramecium cauda- 

 tum ; clones g and i were Paramecium aurelia. (Data of Jennings, '08b; 

 and Jennings and Hargitt, '10). 



culture fluid and temperature, the various clones 

 shifted their mean sizes in parallel fashions, as indi- 

 cated in figure 24. Jennings and Hargitt ('10) obser- 

 ved the persistence of the size characteristics for more 

 than three years, and Erdmann ('20) demonstrated the 



