340 STUDIES IN GENERAL PHYSIOLOGY 



presence of a supernumerary segment leads one to suspect that 

 the regenerated piece might perhaps have developed into a 

 leg in the course of time ; that, in other words, we might 

 have had to do with a heteromorphosis, namely, the forma- 

 tion of a leg in the place of the body segment which had 

 been cut off. Hoek, 1 however, states that the abdomen of 

 Ammothea3 not infrequently shows traces of a segmentation. 



I had the animal shown in Fig. 97 cut into serial sections, 

 which I examined microscopically. The intestine had grown 

 into the anterior portion of the regenerated piece. The 

 tissues were, however, but little differentiated. 



3. The regenerated pieces ab of Figs. 96 and 97 did not 

 make their appearance gradually and then grow steadily 

 larger, but they suddenly appeared with the size and differ- 

 entiation shown in the picture, while on the previous day no 

 regeneration had been visible. As each operated animal 

 was kept in a separate dish upon which its history had been 

 written, and as each animal was examined daily, we must 

 conclude that the regeneration and growth of the new pieces 

 occur slowly under the skin, and that at the next molting 

 the regenerated piece becomes suddenly visible. I have 



1 HOEK, Archive de zoGlogie exp6rimentelle, Vol. IX (1881). 



