POLYZO A. 



INFUNDIBULATA. 



'HE very remarkable beings which now come before our notice are appropriately 

 termed POLYZO A, from two Greek words, signifying "many animals;" because 

 a large number of individuals are massed together in groups of various forms 

 and textures. Some naturalists mostly designate them by the term of Bryozoa, 

 or "moss animals," on account of their frequent resemblance to the various 

 mosses ; but, as this term has been employed in far too wide a sense, grouping 

 under one common designation a number of beings belonging to different classes, 

 the more recent observers have decided on the more appropriate title of Polyzoa. 



For very many years indeed, from the earliest days of natural history until compara- 

 tively modern times the Polyzoa were ranked among the vegetables ; and a learned Italian 

 observer who ventured to express his opinion that they partially, at least, partook of th& 

 nature of animals, was persecuted by the professors of the day with the usual acrimony 

 excited by a discoverer who is in advance of his time. Even the acute and experienced 

 Linnseus could not receive the new doctrine, which was for a while "exploded" by the 

 researches of another naturalist, who announced that he had seen corals in flower, thus setting 

 the question at rest in the minds of those who desired to be so convinced. 



Truth, however, stood its ground, and though for a time suppressed by those who had a 

 personal interest in maintaining the theories which they had so long promulgated, in the due 

 course of events became triumphant. 



The true animal nature of these and many other beings, which had been formerly classed 

 among the vegetables, was at length fairly proved by the researches of two eminent men, 

 Trembley and Ellis, the latter of whom may lay claim to the honor of having produced the 

 best and most comprehensive work of his time ; a work, indeed, which is valuable even at the 

 present day, owing to the invariable clearness and occasional brilliancy of the descriptions, 

 and the number and accuracy of the engravings. 



Ellis called all these creatures by the name of Corallines, a title now given to one of the 

 true vegetables, but discovered many anatomical and physiological details, and set their ani- 

 mal nature beyond a doubt. All his researches were conducted with the aid of instruments 

 which in our day would be thought almost useless, the microscope employed being only a 

 simple lens mounted on a stand, and devoid of the complicated apparatus for magnifying and 

 illuminating that now afford such aid to the observer. 



After the animal nature of the Polyzoa had been fairly established, they were confounded 

 with many other marine and aquatic inhabitants, such as the corals and the various zoophytes, 

 in consequence of the superficial resemblance between their external forms. Lately, however, 

 their true place in the animal kingdom has been discovered, and their affinity with the lower 

 mollusks clearly proved, the tunicates forming the connecting link between the mollusks 

 proper and the molluscoids, as these animals are sometimes called. 



Having glanced at the general history of these curious and really beautiful animals, we 

 will proceed to examine the form and characteristics of the individual species. 



Should the reader obtain from the sea or fresh water a being which is evidently either a 

 zoophyte or one of the Polyzoa, he may set his doubts at rest by examining the tentacles, and 

 if he finds that they are furnished with cilia, or minute filaments, he may assure himself that 

 they belong to the group of animals on which we are now engaged. 



The forms assumed by the general mass of the various species of Polyzoa are extremely 

 different, some resembling twigs or mosses ; others looking like lumps of spongy substance 



VOL. HL . 



