CRISTATELLA. 99 



the intestinal organ and the integument of the body. These do not ex- 

 ceed a tenth part of the size of the prolific ovum ; they are thicker in pro- 

 portion, -with an imperfect row of spines, but wanting the circumferential 

 yellow ring. 



No other mode of propagation has been witnessed than by the pro- 

 duction of an ovum, the formation, protrusion, and liberation of a single 

 hydra from it ; together with the subsequent evolution of additional ani- 

 mals from the same basis that sustains the first. 



Nothing like spontaneous division of the Cristatella has occurred : 

 nor do I know that such division belongs to any product of ascidian 

 nature : I have it not in recollection at the present moment. However, 

 it is not unlikely that two or three specimens may be derived from the 

 accidental transverse rupture of one single specimen having attained matu- 

 rity. Nay, it is possible that portions may be detached from either ex- 

 tremity of long and unwieldy subjects, by the mere embarrassment of mo- 

 tion, position, or restraint. If so, the wounded parts may heal readily. 

 But I am ignorant whether new hydra; will be generated to complete the 

 border. 



Two specimens in contact, occupying the same line, may be mistaken 

 for one by the observer. 



This product has never occurred to me except in tranquil waters. 

 Indeed the soft consistence of its body, and its slight adhesion to any sub- 

 stance, seems little adapted for an abode in the current of flowing streams. 

 Numerous specimens have been obtained from Duddingston Loch, 

 near Edinburgh, and Coldingham Loch, in the county of Berwick ; and I 

 am indebted to the sedulous care of an affectionate relative, the com- 

 panion of all my excursions, the encourager of all my exertions, in so tedi- 

 ous, laborious, and difficult a work, for the finest of any, — that exhibited to 

 the British Association, taken by herself from the garden pond at Binns 

 House, in Linlithgowshire. 



Combining the facts and illustrations afforded by the whole, this wan- 

 dering Cristatella is one of the most wonderful productions of nature ; and 

 one with which no narrow parallel to any other living creature can be 

 drawn, at least I am unacquainted with any to be compared to it. Entire, 



