92 ZOOPHYTES. 



by selection. However, whitish particles were discharged, and the whole 

 specimen continued healthy. 



My belief of a great error may be often repeated, to which I now 

 ascribe many disappointments of a sucessful issue to important observa- 

 tions, in allowing the water with animal products to remain free of muddy 

 matter, whether in accumulation or suspension. Nevertheless, it is im- 

 possible to discover the minutiae of their configuration, as the exterior 

 becomes obscured by the deposition of the invisible suspended particles. 

 Thus, both pure and muddy water may be usefully employed alternately 

 for the same subject. 



This extraordinary being, the Cristatella — a living mass compounded 

 of at least 300 or 350 independent animals, is endowed with an undoubted 

 locomotive faculty, though exercised imperceptibly to the eye. A property 

 so extraordinary and inexplicable, is one of the most singular facts in the 

 natural history of the animal tribes, and that which, were it not verified, 

 we might be prone to call in question, on mere assertion. 



The rate and extent of transition do not exceed an inch in twelve or 

 in twenty-four hours. In the course of it, either extremity indifferently 

 is in advance. The favourite resort of the Cristatella is to half decaying 

 branches of shrubs or trees in still water. If any be deposited there, the 

 animal will be found on them. Sometimes it appears twisted around a 

 twig, so as to form a single long spiral or volute, much after the fashion 

 of certain species of the Doris (Eolis), when applying the long, bare, 

 flexible sole in a similar manner. In default of branches, the Cristatella 

 takes up a position on aquatic plants or on stones. 



Each of the hydra; is independent ; yet, as just observed, how minute 

 the animalculum which may resist one exercise of its faculties. Its simple 

 appearance is enough to deny it strength, though endowed with inclination. 



We may almost presume that the locomotive faculty results from 

 some kind of volition belonging to the common mass — not very intelli- 

 gible indeed, and exacting the concession of its superiority over the sepa- 

 rate or united influence of hundreds of distinct animals, enjoying an inde- 

 pendent will, forming its great border, and carried along as a portion of 

 the whole. 



