Development of Tubulaeia indivisa : — a, a polypite, attached 

 to the extremity of the ccenosarc, bearing clusters of reproductive 

 bodies between the two series of tentacles ; b, one of these clus- 

 ters consisting of several gonophores, borne on a long branching 

 stalk ; c, a single gonophore, containing two young polypites, one 

 of which has commenced to extricate itself; d, the same gono- 

 phore, in a more advanced condition ; e, a young polypite, thirty- 

 six hours after having escaped from the gonophore ; /, the 

 younger polypite, shown within the gonophores c and d ; g, the 

 polypite e, six weeks after extrication, (a is about thrice the 

 natural size : the others are much magnified.) 



Tuhidaria, like Hydra, and, in all probability, 

 many other Hydrozoa, possesses well-marked re- 

 parative powers. When living specimens have 



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