A DISTINCT GROUP. 3 



The celebrity conferred on Trembley by his researches into the structure and economy 

 of Hydra, is known to every one in the least acquainted with the literature of zoology ; but 

 the assiduity of the famous historian of the fresh-water polype was destined to be rewarded 

 by a discovery perhaps just as important as that of the economy of Hydra. It was in the 

 month of April, 1741, that Trembley, while engaged in his researches on Hydra, discovered, 

 in the fresh waters near the Hague, an animal form then quite new to science. It consisted 

 of a lobed jelly-like mass, from which protruded numerous polypoid bodies, each characterised 

 by the possession of an elegant crown of tentacula borne on the margin of a crescent-shaped 

 disc. This beautiful tentacular plume is one of its most striking features ; and as Trembley 

 naturally supposed his animal to be intimately related with the polypes, it suggested the name 

 of "Polype a Panache," by which he subsequently designated it.* 



Almost immediately after this the same species was detected in England by Baker, who 

 subsequently described it under the name of " Bellflower animal.''t Both Trembley and 

 Baker bestowed upon their new animal a careful and accurate examination, and have thus 

 made us acquainted with a very remarkable type of structure — a type, however, whose signi- 

 ficance was destined to remain for nearly a century unrecognised, and it was not until a 

 similar one in certain marine polypoid animals arrested the attention of naturalists, that its 

 importance, and its true bearing on systematic zoology, began to be appreciated. The in- 

 vestigations of Trembley and Baker, however, having clearly demonstrated, in the " Polype a 

 Panache," all the essential characters of polyzoal structure, must be viewed as marking out 

 another most important epoch in tlie progress of zoological research. 



Among the converts which the discoveries of Trembley and Jussieu had made to the 

 animal theory of corals, was Reaumur, who, convinced by their reasoning, withdrew the oppo- 

 sition with which he had met the announcement of Peysonelle, and now ranged himself among 

 the most strenuous supporters of the new doctrine. J Still, however, assent was far from 

 universal, and the greater number of naturalists continued to believe in the vegetability of 

 corals, and denounced the new opinions as false and absurd. Even the celebrated Linnaeus, 

 though he admitted the animality of the stony corals, or lithophytes as he termed them, could 

 never bring himself to express unqualified belief in the animality of those horny and flexible 

 forms which embraced the Tubularidse, Sertularidse, Gorgonise, &c., and most of the Polyzoa 

 of modern zoologists ; and accordingly he took a sort of middle ground, maintaining that 

 these productions possessed a double nature, that their stems and branches grew by a true 

 vegetation and possessed the essential characters of plants, while their polypes were certain 

 inflorescences or developments of the vegetable axis in which the vitality had become exalted 

 from the vegetable into the animal. 



Even this partial admission by Linnaeus of the flexible corals and Polyzoa into the animal 

 kingdom was due to the discoveries of John Ellis, a London merchant, who, amid the 

 engrossing cares of his counting-house, could yet throw open his heart to the love of 

 Nature, and find time for the cultivation of science. In the year 1752 Ellis presented 

 to the Royal Society the result of his first observations on the nature of these 

 creatures. He seems to have then known but little of the labours of his predecessors in 



* ' Memoires pour servir k I'llistoire d'uu Genre de Poljjes d'Eau douce,' Leide, 1741, Mem. III. 



t 'Employment for the Microscope,' London, 1753. 



J ' Memoires pour servir k THistoire des Insectes,' Paris, 1742, tome xvi. Preface. 



