REGENERATION 



685 



gut and ectoderm are flattened against each other. The cells draw 

 away from the region of contact and a new mouth is formed. Tail 

 end regeneration is similar to that at the head end, but simpler since 

 neither brain nor commissures are formed. 



Regeneration in the earthworm is similar to that in Lumbriculus 

 in many respects but is somewhat more complicated. The anterior 

 end, when cut off, regenerates a new tail. "When a head is cut off, 

 another is formed. 



Fig. 366. — Loss and regeneration of appendages in the hermit crab, Eupagurus 

 longicarpus. A, third walking leg; B, next to posterior thoracic leg; B^, posterior 

 thoracic leg ; C, C, C^, abdominal appendages of male ; D, telson and sixth seg- 

 ment with last pair of abdominal appendages ; E, regeneration of new leg from 

 cut-end distal to "breaking joint" ; F, new leg from cut made proximal to the 

 "breaking joint" ; G, leg regenerating from cut made very near the body. (From 

 Morgan, Regeneration, published by The Macmillan Company.) 



