48 



ROBERT W. HEGNER 



Two of the lines are of particular interest, since many speci- 

 mens with 1 or 2 nuclei were obtained from them. Data for 

 the specimens in line ape. 7 are given in table 19 and part of 

 the pedigree of this line is shown in figure 35. The one empty 

 shell produced is not included in the table. The mean diameter 

 of the classes with 3, 4, 5, or 6 nuclei is less than that shown 



19(1) 



28(4) Kl)' 



24(4) 

 26(3) 



Fig. 35 Arcella polypora. Family ape. 7. Pedigree showing diametex's, num- 

 ber of nuclei, and an empty shell. 



in table 15, because specimens were included in each class before 

 the full size normal for that particular number of nuclei had been 

 attained. The class to which attention should be directed in 

 particular is that with 2 nuclei. In this class there were four 

 specimens with a diameter of 19 units; three of 20; four of 21; 

 two of 22; one of 23, and three of 24. The three that were 24 

 units in diameter and the one of 23 units were peculiar, since 

 their nuclei were much larger than those within the other binu- 



