NUCLEOPLASMIC RELATIONS IN ARCELLA 



29 



9 spines and were only from 21 to 25 units in diameter, whereas 

 some of the last specimens in the pedigree had spine numbers 

 of 11, 12, and 13 and diameters of 27, 28, and 29 units. 



Line 153 resembles the lines already described in the rela- 

 tions of the uninucleate, binucleate, and empty specimens, and 

 in the nuclear doubling process. 



2. Line 165. The progenitor of this line was 29 units in 

 diameter and possessed 12 spines.. It was taken from the same 

 line as specimen 153, but was cut into four pieces, as shown 

 in figure 27. The larger nucleated piece was labeled 155a and 



(163) 



i-(153a) 



i(16Jn)) 



18-27 (8) 



10-86(8) 



^9-88(8)- 



-13-86(8) 



Fig. 26 Arcella dentata. Pedigree of part of the specimens in line 153 



the smaller, 155b. The pieces without nuclei died in a short 

 time. The pedigrees of the two lines derived from 155a and 155b 

 are in part shown in figure 28. As in lines 150.2a and 150.2b, 



TABLE 7 



Arcella dentata. Family 153. Table showing variations in spine number and 

 in diameter, of the uninucleates, bimicleates , and empty shells belonging to family 

 153. The unit of measurement is ^.3 m 



