REGENERATION AND LIABILITY TO INJURY 



101 



when cut off at any other level. Schultz states that we see here an 

 excellent example of how regeneration is influenced by natural selec- 

 tion, since regeneration takes place best where the leg is most often 

 broken off. On the other hand, the author hastens to add that since 

 regeneration also takes place when the leg is cut off at any other 



FIG. 38. A-F. After King. A. Starfish with four arms regenerating at different levels. B. Three 

 arms regenerating from disk. C. Arm split in two producing two arms. D. Arm cut off 

 obliquely, regenerating at right angles to cut-surface. E. Starfish split between two aims, 

 producing two new arms from split. F. An arm, with a small piece of disk attached, regen- 

 erating three new arms. G. After P. and F. Sarasin. Starfish (Linckia multiformis) with 

 four new arms springing from end of one arm. Interpreted as a new starfish, but probably 

 only multiple arms (see C, above). 



level, this shows that the power to regenerate is characteristic of all 

 parts of the organism, and is not merely a phenomenon of adaptation, 

 as Weismann believes. It seems highly improbable that a spider 

 could ever lose a leg in the middle of a segment, i.e. between two 

 joints, since the segments are hard and strong and the joints much 



