1 4 BIBLIOGRA PHY. 



animalcules were swimming about in the same water, and its own progressive motion 

 was very swift, it never struck against any of them, but directed its course between 

 them, with a dexterity wholly unaccountable, should we suppose it destitute of 

 sight." 



Henry Baker's speculations concerning the probable origin of animalcules 

 in hay and other infusions will be referred to in a future chapter. 



Abraham Trembley's name, while most famous in association with his 

 remarkable discoveries concerning the extraordinary recuperative properties 

 after mutilation possessed by the fresh-water polypes, Hydra vulgaris and 

 viridis, has also to be included in the list of contributors to our early 

 knowledge of the Infusoria. In the course of his investigations and expe- 

 riments upon the more highly organized forms just mentioned, he was the 

 first to encounter many of the larger Stentors or trumpet-animalcules, and 

 regarding them as structurally allied to the latter, described them in the 

 ' Philosophical Transactions ' for 1744 under the respective titles of the white, 

 blue, and green funnel- or tunnel-like polypes. Through a prolonged study of 

 these forms Trembley made himself familiar with, and recounted at length, 

 the peculiar oblique manner in which they subdivide, the mode in which 

 the new head and oral aperture is formed upon the posterior segment, and 

 a new caudal prolongation upon the anterior one, being related with such true 

 and exhaustive detail as to leave but little to be added in this connection 

 by later investigators. Under the title of " Clustering Polypes " this 

 authority also figured and described several varieties of Epistylis, notably 

 E.flavicans, relating precisely the manner in which by constant and even 

 longitudinal subdivision and prolongation of the supporting pedicle the 

 branched compound colony is built up. This premised affinity of the trumpet- 

 animalcules with the polypes suggested by Trembley received the full 

 approbation of the father of systematic natural history, the immortal and 

 illustrious Linnaeus, by whom they were included in the tenth edition of his 

 famous ' Systema Naturae,' published in the year 1758, under the title of 

 Hydra stentorea. 



Five years later, 1763, we find for the first time the term "Infusoria" 

 introduced for the distinction of the minute beings that form the subject 

 of this treatise. M. F. Ledermuller, of Nuremberg, to whom must be 

 awarded the credit of creating this highly suggestive title, which has since 

 been almost universally adopted, employed it in the first instance for 

 the distinction of all those microscopically minute animals discovered by 

 himself and earlier investigators in water in which hay had been for some few 

 days previously steeped. This new title he further proposed to extend to 

 all the microscopical forms of animal life inhabiting infusions and putrid 

 liquids, including also those discovered in stagnant rain-water nearly a 

 century previously by Leeuwenhoek ; the Stentors were, nevertheless, left by 

 him in the position among the polypes assigned to them by Linnaeus and 

 Trembley. The names of Rosel, 1755, Wrisberg, 1765, and Pallas, 1766, may 

 be mentioned among the more prominent contributors to our earliest know- 



