REACTIONS OF CELL-BODIES OF DIFFLUGIA. 31 



pod at 10:44 A.M. This soon became greatly contorted, and 

 from its tangled mass two amoeboid fragments emerged. The 

 water became shallow soon after the operation and it was necessary 

 to add more, which separated the fragments a considerable dis- 

 tance from the cell-body. At 11:16 A.M. the fragments were 

 placed in the vicinity of the cell-body again (Fig. 6 — A, a, b). At 

 11:23 A.M. fragment a had shifted its axis so that it now lay 

 directed toward the mouth of the animal's shell. Fragment b, 

 during the same period, traveled to position x. The cell-body was 

 now pushed up to the relative position shown at B without dis- 

 turbing the fragment. The anterior tip of fragment b was imme- 

 diately shifted so that it was now directed toward the new position 

 of the shell's mouth. The entire fragment had advanced to posi- 

 tion y by 1 1 : 27 A.M. At this time fresh water was added to the 

 slide, and in doing so the fragments were lost. 



That such enucleated fragments show a positive response to 

 stimulus, whatever it be, seems unquestionable. The importance 

 of this is, perhaps, emphasized by the fact that all fragments 

 involved in our observations were not simply enucleated bodies of 

 protoplasm, for endoplasm did not constitute a portion of any of 

 them. They were, therefore, enucleated ectoplasmic fragments. 



V. Will Two Enucleated Fragments Fuse with Each 



Other? 



Having observed the readiness with which fusion took place 

 between Difflugia and its ectoplasmic fragment, the question sug- 

 gested itself — Is there a tendency between two pieces of protoplasm 

 to fuse when no restitution of a cell would result from such a 

 fusion ? Not a sufficient number of experiments has been per- 

 formed to warrant an emphatic statement in regard to this point. 

 But at least twenty observations have been made in which two or 

 more fragments from the same organism were involved. In these 

 experiments the fragments were only ectoplasmic in composition 

 and varied in size from five to twenty micra in diameter. The re- 

 sults of these experiments can be illustrated by the following 

 example : 



A large and a small fragment were cut from a Difflugia spiralis, 

 after which the animal was removed from the slide. The frag- 



