IVII.KAt I lo\S OF PROTOPLASMIC MASSES. I IJ> 



which this line wa~ nourished). Ordinarily lines were perpetua- 

 ted through the individuals remaining in the old shells, but this 

 rule was not strictly adhered to since experience showed no differ- 

 ence in tin- results obtained when other members were used. 

 From two to four individuals of each line were kept in culture as 

 a precaution again-t possible fatalities. 



I SIMILAR ENVIRONMENTS. 



These experiments are discussed under the heading "similar* 

 environments because the external conditions surrounding the 

 two lines of the clones involved were as nearly alike as it was 

 possible for the experimenter lo make them. Though kept apart 

 from the first division of the clonal parent, the two diverging 

 lines were treated in exactly the same manner; for instance: t In- 

 same pipette was used in transferring members to fresh concavi- 

 ties; these concavities contained culture medium taken from the 

 same bottle; afterwards the depression slides containing the 

 organisms were placed alongside each other in the same moist 

 chamber. Frequent tests were made, according to the method 

 described above, between individuals of one line and fragments of 

 protoplasm from individuals of the other. It was found that 

 daughter-cells (members of the second generation) would readily 

 fuse with each other's severed fragments and that such reactions 

 would occur regardless of whether or not the organism taking up 

 the fragment had just previously lost a part of its own protoplasm. 

 Furthermore, in every case when both lines were kept under 

 similar conditions, cross-fusions continued to be exhibited for 

 fifteen or more generations; consequently in later experiments 

 tests for interactions were not begun until several generations 

 had elapsed. 



A series of experiments conducted between the two lines of 

 clone I are given in extenso in Table I. It \\ill be seen by re- 

 ferring to this table that cross-fusion between line i and line id 

 persisted until the 22d day and 24th generation. After this no 

 further inter-fusions occurred, but in-tead the prot..pla-ms usu- 

 ally were shattered upon making contact. Attention -hoiild be 

 called to the fact that in some of the experiment li-ted in Table I. 

 the organism was on its back when placed near the fragment ; in 

 other cases the fragment would become detached from the sub- 



