100 ZOOPHYTES. 



the parent of the whole ; that their progress is derived from the animated 

 portion alone of compound subjects, that which, to our apprehension, is ex- 

 clusively endowed with life, sensation, and action : for although what we 

 call the inorganic parts be indispensable, and form the instrument of the 

 general union and connection of all, nothing denoting active animal fimc- 

 tions is to be detected there. 



The increment of zoophytes might have been explained as effectually 

 perhaps from the multiplication of the fresh-water hydrse. — Plate XII. 

 figs. 15-20, and the Vorticella, Plate XXI. But the superior dimensions 

 of the subject I have chosen, the facility of preservation, and the certainty 

 of witnessing its prolific qualities in the most convenient position, under 

 suitable, simple, and easy treatment, render it infinitely preferable to the 

 others. The chief obstruction to the wishes of the naturalist concentrate 

 in the difficulty of obtaining specimens, for there is no known guide which 

 can lead to their disovery. 



The hydraoid zoophytes multiply in general by simple divergence to 

 rio-ht and left in the same plane, a character peculiar to most of the asci- 

 dian zoophytes also, especially of the foliaceous genera. At the same time, 

 multiijlication by ascent is advancing in both, whence may be compre- 

 hended the rapidity wherewith vigorous specimens shall reach to thou- 

 sands. 



Strict conformity subsists between the increment of these and of the 

 Hydra tuba. The original parent remains, in all, the lowest of the colony, 

 or amidst the progeny diffusing around it. But there is one noted diffe- 

 rence not to be overlooked. The Hydra tuba survives the birth of its 

 own young, and also of their progeny, for some indefinite period ; but the 

 original parent of the Sertularia and the Flustra perishes as its posterity 

 continue increasing by successive generations. 



However, I shall rather reserve for the conclusion of this treatise a 

 brief review of some leading principles governing the nature of such zoo- 

 phytes, as have led us into more diffiise discussion in its course. 



Meantime, let us consider how vast the proportion of the lower 

 animals incorporated with the various hydrse in their more comprehen- 

 sive si"-nification ; that multitudes in one or other stage are connected 



