466 



BIOLOGY OF THE PROTOZOA 



other case the sixteen macronuclei would all fuse to form one single 

 macronucleus which would divide and form two groups of eight each 

 (Fig. 196). In the latter case there was not only a definite adapta- 



FiG. 194.— Uroleptus mobilis; orij^in of doutile individual. Above, two conju- 

 gating cells; below, the double individual which was formed by the fusion of two such 

 conjugating individuals. (Original.) 



tion to the new conditions but a further advance toward a com- 

 posite animal of a new type and with a novel organization. The 

 synchronous activities indicate that common responses to common 



