REPRODUCTION OF EUDENDRIUM. Ill 



single, in pairs, or in clusters of seven or eight toge- 

 ther (PL II. fig. 2,/). 



These yellow plums proved at length to be so many 

 ovaria, analogous to the clustering cysts of Tubularia 

 already described, though differing from these latter 

 in various particulars ; for they neither corresponded 

 in position or consistence, nor in the connexion of a 

 number by a pedicle affixing them to one common 

 stalk, nor in their contents. 



Each of these minute yellow plums is a separate 

 and independent pod or vesicle, from which is dis- 

 charged an animal intimately resembling a Planaria, 

 and which Sir John Daly ell designates a Planula. 



This animal, the Planula (PL II. fig. 2, e), is taper, 

 roundish, or somewhat flattened, not half a line in 

 length, of smooth, uniform, fleshy aspect, and quite 

 destitute of external organs. It crawls along the 

 bottom with considerable activity ; and on ascending 

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

 either descends again, or, committing itself to the 

 element, it swims supine : it changes its situation 

 freely, testifying evident preferences, and is of in- 

 finitely greater activity than the nascent Hydra dis- 

 charged from the cyst of Tubularia. 



The Planula is soft and variable in its form, and it 

 continues crawling about for an indefinite time. Then 

 its motion relaxes, it shortens and thickens, and 

 appears as if composed of two portions, a larger and 

 smaller, both very obtuse, and shortly afterwards it is 

 found fixed to some solid substance. In four days 

 more it becomes altogether metamorphosed, for now 

 it is found changed into a living Hydra, borne on a 



