370 



ESSENTIALS OF ZOOLOGY 



Regeneration and Autotomy 



Regeneration is the name applied to the power some animals have 

 to replace mutilated or lost parts. The starfish has this phenomenon 

 quite well developed with regard to its arms. Any or all of the 



I Madreporite 

 Reqeneratinq rctj 



Fig. 141. — Regeneration in the starfish. Above, a starfish regenerating part of 

 the central disc and three arms ; below, arm of starfish regenerating the remainder 

 of the body. 



arms of the starfish may be lost and the missing parts regenerated. 

 An arm with a small portion of the central disc will regenerate the 

 missing parts under favorable conditions. A mutilated arm or one 

 caught in the grip of some enemy may be cast off by breaking loose 



