HEREDITY IN THE PROTOZOA 291 
Hegner has. studied similar problems on another 
form, Arcella dentata (Fig. 68), in Jennings’ labo- 
ratory, and has fully confirmed Jennings’ and 
Middleton’s results. Hegner has made a number 
Cis, 
Fig. 69.—Arcella dentata. A, mononucleate individual. B, non- 
nucleate, and C, binucleate individual, products of division of mono- 
nucleate individual. D, descendant, and £, later descendant of C, ap- 
proaching normal size. (After Hegner.) 
of other experiments and observations that have a 
bearing on the influence of the nuclei and of the 
chromidial net of Arcella. In one species, A. dentata, 
there are two nuclei situated opposite to each other 
as seen in A, Fig. 68. If an individual is cut in 
