hunt: regenerative phenomena in earthworms. 575 



Number 77. Eisenia foetida. The closed digestive tube after 

 fifty days was about the length of four segments from the healed 

 anterior end of the body. A brain had regenerated, which was joined 

 with the ventral nerve cord by abnormally short connectives. The 

 sagittal sections of the brain were less than half the average size of 

 corresponding brain sections from four normal animals of the same 

 species. 



Number 294- Eisenia foetida. This case resembled number 77 in 

 every essential respect, but differed from it in the following details. 

 In median section the brain was only about one fourth as large as a 

 normal brain. The regenerated connectives were longer and slenderer 

 than in mmiber 77, and one nerve had begun to grow forward from 

 the regenerating brain. 



Number 291. Eisenia foetida. Fifty days after operation the 

 worm had regenerated a colorless, blunt, anterior region, which was 

 divided externally into three or four segments (Fig. 3, A to B). The 

 drawing was made while the worm was under the influence of the 

 anaesthetic. The furrows were certainly intersegmental grooves 

 and not the results of muscular contraction in the regenerated region, 

 for the muscles must have been relaxed under the influence of the 

 anaesthetic. A study of the sagittal sections also shows the seg- 

 mented character of the new tissue, for the intersegmental grooves 

 could be traced down one side of the animal, across the ventral sur- 

 face, and up the other side. In many places the epidermis at the 

 bottom of these grooves was, as in normal intersegmental grooves, 

 distinctly thinner than elsewhere. The digestive tube was about 

 three segments posterior to the place where the regenerated tissue 

 began. A thin layer of slender circular and longitudinal muscle 

 fibers had regenerated in the normal positions for such fibers. The 

 new brain and connectives united in normal fashion with the nerve 

 cord, although sections of the brain were only about one fourth as 

 large as corresponding sections of the normal brain. This case is 

 unique because it demonstrates that segment formation is independent 

 of the close proximity of the digestive tube to the regenerating region. 



Number 272. Eisenia foetida. The digestive tube was about five 

 segments from the regenerating end of the body after fifty-four daj^s. 

 An invagination in this regenerated tissue was clearly a stomodeum 

 (Fig. 4, stmd.). This was demonstrated by its normal shape (as 



