1908.] 



JENNINGS -HEREDITY IN PROTOZOA. 



413 



polygons of Diagram 3. It is evident that the variability has become 

 much greater in the rapidly growing culture. The range of variation 

 of length in the stationary culture is from 148 to 212 microns; in 

 the growing culture it is from 104 to 220 microns, so that in the 

 latter the range has almost doubled in extent. The coefficient of 

 variation in length has likewise almost doubled, changing from 7.794 

 when the culture was stationary to 13.262 when it was growing. 

 For breadth the range of variability has likewise increased consid- 

 erably, though the coefficient of variability shows little change. The 

 correlation between length and breadth has become considerably less 

 in the rapidly multiplying culture, decreasing from .5955 to .3945. 

 The mean length has slightly decreased, the mean breadth slightly 

 increased, in the growing culture. 



104 116 128 140 152 164 172 188 200 212 224 



Length in ^Microns. 



Diagram 3. Polygons of variation in length for (a) a culture of de- 

 scendants of D that is rapidly multiplying and (&) one that is not. The 

 continuous line represents the rapidly multiplying culture of Table VII. ; the 

 broken line the stationary culture of Table VI. 



From this example it is clear that growth and multiplication may, 

 and probably do, play a large part in determining the character and 

 distribution of the variations, as well as in determining the mean 

 dimensions and their correlations. We shall now attempt to deter- 



