58 ZOOPHYTES. 



which bore fine florid hydrae, like those of the Tubularia represented 

 Plate VII., I found minute yellow objects like plums, as before, on different 

 parts ; two on some, and on others five or six. Many of the hydrae exhi- 

 bited symptoms of decay, when these were in their immediate vicinity. 

 All were preserved with equal care as previously. 

 The yellow plums proved at length to be so many ovaria, analogous 

 to the clustering cysts already described in detail, though differing some- 

 what in various particulars ; for they neither corresponded in position or con- 

 sistence, nor in the connection of a number by a pedicle affixing them to 

 a common stalk, nor in their contents. In fact, they may be almost iden- 

 tified with the vesicles or pods borne by the Sertularise, which remain for 

 ample discussion in their proper place. 



Each of these minute yellow plums is a separate and independent 

 pod or vesicle, wherein, no doubt, an ovum is originally generated, but 

 discharging an animal intimately resembling a Planaria, and which, for the 

 purpose of ready and familiar recognition, I shall venture to designate 

 flmudii. The conventional name of larva, which there is at present so 

 strong a disposition to incorporate in the vocabulary of natural history, 

 seems scarcely enough expressive of its character. 



Only a single large bright yellow planula is contained in the vesicle, 

 whence it is discharged on maturity from an orifice towards one side near 

 the summit. But the vesicle itself is of such extreme transparence, that 

 it is hardly visible, after losing its contents. 



This animal, the planula, is taper, roundish, or somewhat flattened, 

 not half a line in length, of smooth, uniform, fleshy aspect, void of exter- 

 nal organs. It crawls with considerable activity below ; and on ascending 

 by the side of its vessel to the surface of the water, it either descends 

 again, or pursues a course at the edge ; or committing itself to the element 

 it swims supine. It changes its situation freely, testifying evident pre- 

 ferences, and it is of infinitely greater activity than the nascent hydra after 

 being discharged, and during its evolution from the cyst of the Tubulario 

 indwisa.—V\. VIII. fig. 7. 



Certain learned naturalists, whose opinion I highly respect, have ex- 

 pressed their doubts of the animation of this being, without having seen 



