292 ZOOPHYTES. 



though these animal products be not strictly incorporated with zoophytes, 

 remarkable analogies are discovered between them. This may not appear 

 so strange, on reflecting that many distinct analogies between the animal 

 and the undoubted products of the vegetable creation, can be described, 

 though infinitely farther apart. 



Here, a capsule or integument containing the embryo, is generated 

 in the fleshy portion of the compound ascidia, at least it is there that we 

 first find the object. This object is discharged singly, somewhat as the 

 contents of a single cyst of the Tubularia indivisa, being an integument 

 covering a minute animal, intimately resembling a tadpole or common pin. 

 Thence, for the facility of recognition, it is denominated spinula. 



This minute creature quitting its capsule or integument, is active, 

 wriggling its way like a tadpole through the water. Like the tadpole, 

 also, its form consists of a head and a tail. Its motion is arrested, the 

 head adheres to the surface of the glass below, while the tail, at 

 first remaining upright, soon wastes away and disappears. Mean- 

 time eight originating radicles rivet the head to its position, and they 

 also wasting away, the head of the spinula in adhesion, is in a short 

 time metamorphosed to an Ascidia. But this does not exhaust the gene- 

 rative process, for with the compound Ascidia?, a second young Ascidia 

 developes beside the first that came from the original spinula : then a 

 third ; and next a fourth, and thus of others, to augment the specimen : 

 All, however, without the intervention of a second or additional spinula. 



The animated productions of Nature are wonderfully advanced 

 through various successive stages, generally so different from each other, 

 that unless by following their progress, the existence of the same being 

 could not be identified. These changes are denominated metamorphoses ; 

 because they seem the transformation of one subject to another, though, 

 let us repeat, their principles and their course are very insufficiently 

 understood. 



Metamorphosis, however, seems always for the purpose of advancing 

 towards perfection. Nature pursues a uniform course, and as the Author 

 of the universe seems, by his mighty fiat, to have determined the distinct 

 existence of every separate race, that each shall remain in its own indi- 



