TUBULARIA. 71 



phyte. One wherein no subordinate organic parts were visible, on first 

 inspection, was observed to unfold in three hours. 



There is reason to believe that this Medusa is confined in a diapha- 

 nous vesicle or involucrum, remaining in its place after the animal has 

 escaped. If actually so, which requires confirmation, we cannot but re- 

 cognize strict analogy to the vesicles of the Sertularise, some being hardly 

 perceptible after discharging their contents, from extreme transparency. 



A colony computed at 130 individuals of the Medusa ocilia, was pro- 

 duced in four or five days : and there are grounds for assuming that suc- 

 cessive colonies come from the same specimens of the zoophyte. 



I cannot presume to afiirm that any connection, immediate or remote, 

 connects the Medusa ocilia and the Tubularia ramosa ; far less to conclude 

 that the former shall be metamorphosed in progress of time to the latter, 

 with its numerous and beautiful appurtenances. I have not seen both 

 the beginning and the end ; nor does the fugitive existence of so delicate 

 a creature seem well adapted for permanent observation. 



This is not the only example, it is true, which I have witnessed of 

 Medusarian forms originating from hydraform products, as shall be ex- 

 plained in the proper place. But we cannot be too distrustful of infer- 

 ences on such obscure and peculiar phenomena of nature. So many im- 

 portant facts may elude observation, so many delusive appearances are 

 ready to bewilder the senses, we cannot desire too ample corroboration. 



Perhaps the preceding facts, as well as the subsequent, may stimulate 

 more intelligent naturalists, enjoying better opportunities than I have had, 

 to seek their confirmation. 



Plate XI. Fig. 1. Tubularia (Sertularia) ramosa, investing part of the Virgu- 

 laria (Fennatula mirahilis,) or Sea Pen. 



2. Branch. 



3. Hydra protruding from the extremity of a twig, a. 



4. Hydra with an indefinite excresence on the neck. 



5. Hydra with three pyrula a (embryonic medusae) at the orifice 



of the twig. 



6. Pyrula at the extremity of a branch. 



