NUCLEOPLASMIC RELATIONS IN ARCELLA 



27 



c. Experiments on members of family 152 



The specimens thus far described were all members of family 

 150. It is interesting, however, to know if the results of remov- 

 ing nuclei and cytoplasm are similar in other families. The 

 original progenitor of family 152 was collected from the pond 

 on December 27, 1917, and like specimen 150 its spines were so 

 minute that they could not be counted. It was 31 units in 

 diameter. The first offspring also lacked fully developed spines; 

 it was 32 units in diameter. This specimen was cut in two 

 (fig. 24) and fifty descendants were reared from one of the 

 halves. These consisted of uninucleates, binucleates, and empty 

 shells, and these various members were interrelated just as 



TABLE 6 



Arcella dentata. Family 152. Table slwwing variations in spine number and in 

 diameter of the uninucleates, binucleates, and empty shells belonging to family 

 152 {line 152.1a). The unit of measurement is 4-3 microns 



were those of line 150. Table 6 gives the variations in spine 

 number and in diameter, and the mean spine number and mean 

 diameter of the 50 specimens in the line. The means of the 

 binucleates are too low, since they were computed largely from 

 the offspring of specimens that had just undergone nuclear 

 doubling and had not yet reached the size characteristic of the 

 race. 



The experiments on members of this family thus confirm 

 the results derived from a study of family 150, and demon- 

 strate that the processes described in the latter are similar in 

 families derived from different wild specimens. 



