140 



THE BIOLOGY OF STENTOR 



(d). Considering this case as a mid-point, the range of interactions 

 was from one extreme of prompt and complete primordium 

 resorption to the other, or precipitous induction of anlagen 

 formation. 



Where the final result will lie within this spectrum depends 

 upon the stage of the original primordium, the relative volume of 

 the two cells, and the intimacy of their union. As we shall see in 



A 



B 



C 



D 



Fig. 35. Activation-inhibition reactions in parabiotic stentor 



grafts. 



