NUCLEOPLASMIC RELATIONS IN ARCELLA 



71 



TABLE 30 



Table showing the differences in diameter between the chromatin masses of the two 

 members of the pairs of nuclei in specimens from families 150.2b and 58eg. of Arcella 

 dentata and families ap. 5 andap. S4, of A. polypora. The nuclei of the living 

 specimens were drawn at a magnification of 900 diameters and then their diameters 

 were measured in units of 0.25 mm. 



150.2ba 

 58eg... 

 Ap.5... 

 Ap.34. . 



Mean difference 

 between mem- 

 bers of pairs 



1.50 



.98 



1.47 



1.26 



h. Chromatin mass and cell size within two families of Arcella 



polypora 



The chromatin-mass condition within families ap. 5 and ap. 34 

 of Arcella polypora was more difficult to determine because of the 

 larger number of nuclei and their smaller size. However, satis- 

 factory camera drawings were made of the chromatin masses of 

 twenty-five specimens in each family. The number of chroma- 

 tin masses in a specimen ranged from 5 to 7 in family ap. 5 and 

 from 4 to 10 in family ap. 34. Only the drawings of three chro- 

 matin masses of each specimen were measured, thus giving sev- 

 enty-five measurements for each family. Table 31 shows that 



TABLE 31 

 Arcella polypora. Table showing the distribution of the diameters of three of the 

 chromatin masses in twenty-five specimens each of families ap. 5 and ap. 34- The 

 chromatin masses within the living animals loere drawn with a camera lucida mag- 

 nified 900 diameters, and the diameters of these drawings were then recorded in 

 units of 0.25 mm. 



