INTERACTIONS OF PROTOPLASMIC MASSES IX RE- 

 LATION TO THE STUDY OF HEREDITY AND EN- 

 VIRONMENT IN ARCELLA POLYPORA. 1 



BRUCE D. REYNOLDS, 



FROM THE DEPARTMENT OF MEDICAL ZOOLOGY OF THE SCHOOL OF HYGIENE AND 

 PUBLIC HEALTH. JOHNS HOPKINS UNIVERSITY, BALTIMORE, MARYLAND. 



INTRODUCTION. 



In the first article of this series, Kepner and Reynolds ('23) 

 have shown that under favorable conditions Difflugia usually 

 reappropriates, by fusion, fragments of protoplasm which have 

 been severed from the cell-body. In the last paragraph of their 

 summary these authors make the following statement: "Obser- 

 vations have been made in which individuals of the same species 

 obtained from the same wild culture, showed a decidedly nega- 

 tive response towards each other's fragments, yet in other 

 instances such cross-fusions did occur." Elsewhere in their 

 paper two suggestions are made as to the probable explanation 

 of why some specimens did fuse \vith fragments belonging to 

 other individuals, viz: "(a) The individuals were closely related 

 by having a recent, common ancestor, (b] By living in the same 

 surroundings, the environmental influences have acted upon both 

 organisms in such a way as to cause an identical physiological 

 The question thus raised seemed to be of sufficient im- 

 portance to justify further work on the subject; consequently 

 the experiments incorporated in this paper were conducted for 

 the purpose of clarifying the situation. 



The previous publication was largely concerned with describing 

 the process of protoplasmic fusion. Although a number of 

 observations were made upon the reactions between cell -bodies 

 and fragments from other individuals of the same species, no 

 attempt was made to culture the organisms and then test for 

 reactions between members of a clone. As a result, only two 



1 This is the second article of a scries dealing with the phenomenon of fusion 

 between protoplasmic masses. The first article was written by Win. A. Kepner 

 and B. D. Reynolds ('23) from the University of Virginia. Further work on the 

 subject is now in progress. 



1 06 



