INFUSORIAL ANIMALCULES. 4l 



of sense, their nerves and vessels, cannot be exactly determined, and 

 everything inclines one to believe that these animalcules, although 

 endowed with a degree of organization, in accordance with their 

 mode of life, cannot possess the same systems of organs as do the 

 superior animals." 



" The coloured points, for example, commonly red, wlaich have 

 been regarded as eyes, cannot, "nith the least certainty, receive that 

 appellation." (Ann. des Sciences, 1840.) 



The recent opinions of Siebold are opposed to those arrived at by 

 the observations of Ehrenberg. 



Siebold does not regard the vesicles or sacs, as digestive organs ; 

 and the existence of an intercommunicating intestine between them, 

 is altogether denied. The Astoma (mouthless animalcules) are 

 described as noiuished only by a general absorption from the surface. 

 In the Stomatoda, with evident mouths, Siebold represents the mouth 

 as continued into the interior by a sort of oesophagus, wide, differing 

 in length, and straight, ciu'ved, or even spiral, terminating abruptly 

 in the general loose parenchyma of the body. When food is sought, 

 it is drawn towards the mouth by the action of the siuTounding cilia, 

 and having been received into the mouth, enters the cesojihagus, and 

 is thence pushed onward by a contraction of the part, in the form of 

 a rounded globule, and enters the loose interior parenchyma. The 

 food, so introduced, appears mostly like a minute drop of water, it 

 may be holding some solid particles in suspension, after a longer or 

 shorter sojoui-n in the interior, and a greater or less cii'cuit, it is in 

 most Stomatoda ejected thi'ough a distinct and fixed anal outlet, and 

 not as Dujardin states, from any portion of the sui'face indifferently. 

 The anus is generally situated at the opposite extremity of the body 

 to the mouth, and on the luider surface, when this orifice is wanting, 

 the nutriment matter is both received and expelled by the mouth, as 

 in Polype. (See Microscopic Cabinet, Plate VII.) 



The possession of distinct walls by the vesicles is also not admitted 

 by Siebold, since coalescence is sometimes seen to occiu- between 

 them. That there is no connecting intestinal tube, is, to the same 

 observer, proved by the great mobility of these globules in the 

 parenchjona, as well as by the fact, that the nutritious particles, fii'st 

 and last swallowed, become mingled confusedly together ; and lastly, 



