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TEXTBOOK OF ZOOLOGY 



B 



Mill LLL 



Fig. 364. — Stentor coeruleus, showing regeneration. A, cut into three pieces ; 

 B, shows progress of development of anterior portion ; C, progress of regeneration 

 of middle piece; D, progress of regeneration of posterior piece. z (From Morgan, 

 Regeneration, by permission of The Macmillan Company.) 



Porifera 



Some of the sponges have very extensive capacity for regenera- 

 tion. A series of classic experiments by Prof. H. V. Wilson of 

 North Carolina demonstrated that regeneration is possible after the 

 dissociation of the cells comprising the bodies of monaxonid sponges 

 by pressing them through gauze. The individual cells thus sepa- 

 rated come together in groups. These cell groups organize them- 

 selves into spheres, then grow and develop into new sponges. Dif- 

 ferentiated cells, as well as the undifferentiated amoebocytes, take 

 part in regeneration. 



Coelenterata 



The coelenterates have been the subject of very extensive experi- 

 ments on regeneration. In general, members of this group may be 

 cut into fragments and each fragment will regenerate a complete 

 individual. Some forms, such as Eudendrium, are capable of regen- 

 eration after dissociation in the same manner as the Porifera. 



