374 CHAS. W. HARGITT. 



having the appearance in many cases of embryonic morulse, or 

 blastulae. It was this phenomenon among others already men- 

 tioned which first raised the question in my mind as to their 

 regenerative possibilities many years ago. Concerning the mode 

 by which this process of aggregation is brought about there is 

 some doubt. The attempt was made to actually observe it by 

 carefully keeping a fresh culture under direct observation with 

 the microscope. It was thought that the action of the flagellated 

 cells of the entoderm might act as a means by causing vortices 

 in the water, but careful study failed to show that this was a 

 factor of any direct value. Such action of these cells rnay be 

 easily seen but its effects are as often repellent as attractive. 

 The fact that certain of the cells show amoeba-like aspects sug- 

 gested a possible amoeboid action in the process. But here again 

 no evidence whatever was found to prove the suggestion. One 

 might imagine some chemo tropic influence, but no evidence was 

 found that such was the case. I am inclined to the view that 

 chance contact is perhaps the chief factor in the process. This is 

 made probable by the fact that such aggregation may be greatly 

 facilitated by mechanical agitation of the cells, and by a gentle 

 rotary motion of the dishes. In the earher experiments con- 

 siderable care was taken to handle the dishes as little as possible 

 during the early stages of an experiment, thinking such might 

 be undesirable, but later the opposite view was taken, and the 

 dishes often rotated to hasten the process. It must be admitted, 

 however, that there seemed to be other factors involved, for 

 even when a considerable mass of cells had been brought together 

 by this means there was later found to have been a sort of segrega- 

 tive process at work, for the mass had been more or less broken 

 up into sections or lobes which later behaved as entirely inde- 

 pendent bodies. 



The cell aggregates, while rather predominantly sub-spherical 

 in shape, showed considerable variation. Some were flattish, or 

 disk-like, and some were somewhat lobulated and irregular in 

 shape. But throughout a series of such aggregates one of the 

 most conspicuous features was that already referred to above, 

 namely, the resemblance to an embryonic blastula or morula, 

 especially a hydroid morula; and if one were to take account of 



