178 



Regeneration 



gone hydrolysis in order to furnish the nutritive material 

 for the new head and tail, since the piece cannot take 

 up any food from the outside before a mouth is formed. 

 These phenomena of autodigestion — the process itself 

 will be discussed in the last chapter — seem to occur in 

 many (if not all) phenomena of regeneration. It may 



be that the collect- 

 ing of red cells at 

 the end in a Tubu- 

 larian where regen- 

 eration is about to 

 begin has to do with 

 the furnishing o f 

 material by self- 

 digestion, since these 

 cells are partly at 

 least destroyed in 

 the process. It is of interest to look for more ex- 

 amples of autodigestion accompanying phenomena 

 of regeneration. 



The writer has observed more closely the transforma- 

 tion of an organ into more undifferentiated material in 

 Campanularia (Fig. 33), a hydroid.^ This organism 

 shows a remarkable stereotropism. Its stolons attach 

 themselves to solid bodies, and the stems appear on 

 the side of the stolon exactly opposite the point or 

 area of contact with the solid body. The stems 



' Loeb, J., Am. Jour. Physiol., 1900, iv., 60. 



Fig. 33 



