The Fusion of Individuals 105 



A method. The problem of size-regulation may re- 

 ceive important elucidation if and when it is found pos- 

 sible to control conjugation more accurately than has 

 heretofore been attained. Plastogamies might be in- 

 duced at will if the nuclear fusions, or merely the nu- 

 clear reduction divisions, could be inhibited after union 

 of cytoplasms has been completed. Stolte ('24) de- 

 scribed in Blepharisma certain naturally occurring 

 "conjugations" which gave rise to reorganization of 

 the nuclei without any fusion of or exchange of nu- 

 clear material. Thus the nucleoplasms of the two 

 individuals remained distinct while the cytoplasms 

 united; it is necessary to study further the conditions 

 under which the union will persist when once it has 

 thus spontaneously begun. 



What constitute the differences between agamic fu- 

 sion and gamic fusion ? The answer, when found, may 

 carry with it important corollaries concerning the 

 regulation of size of the entire body, of mass of nuclear 

 material, and of capacity for multiplication or further 

 synthesis of more protoplasm in the race. 



3. Cannibalism 



When an individual engulfs another individual of its 

 own species the result resembles, in some respects, a 

 fusion of the individuals. Although in no cases the ac- 

 quired bodily material is directly incorporated, the 

 bulk of the body is apparently increased more rapidly 

 thereby than by any other means. Whereas, with a 

 few exceptions, those food materials which are ac- 

 quired in living or in solid form are small in bulk com- 

 pared with the assimilating individual, those acquired 

 by cannibalism form a relatively large bulk of nutri- 

 tive substances in exactly the proper proportions for 

 growth. A mass approximately equal to the bulk al- 

 ready owned by the cannibal is acquired at one gulp. 



