416 



MICROSCOPIC FORMS OF ANIMAL LIFE. 



FIG. 196. 



kind of muscular fibre, and is probably nothing else than a portion 

 of sarcode specially endowed with this property. Nothing but 



the rapidity of its contraction and 

 relaxation differentiates it from 

 the pseudopodia of the Ehizo- 

 pods. There is no reason what- 

 ever to believe that these Animal- 

 cules possess any organs of special 

 sense. The red spots which may 

 be seen in many of them, and 

 which have been designated as eyes 

 by Prof. Ehrenberg, from their sup- 

 posed correspondence with the eye- 

 spots of Rotifera ( 278), really bear 

 a much greater resemblance to the 

 red spots which are so frequently 

 seen among Protophytes ( 153). 

 If they are really endowed with 

 consciousness, as their movements 

 seem to indicate, though other con- 

 siderations render it very doubtful, 

 they must derive their perceptions 

 of external things from the impres- 

 sions made upon their general sur- 

 face, but more particularly upon 

 their filamentous appendages. 

 269. The interior of the body does not always seem to consist 

 of a simple undivided cavity, occupied by soft "sarcode;" for 

 the tegumentary layer appears in many instances to send pro- 

 longations across it in different directions, so as to divide it into 

 chambers of irregular shape, freely communicating with each 

 other, which may be occupied either by sarcode, or by particles 

 introduced from without. The alimentary particles which can 

 be distinguished in the interior of the transparent bodies of 

 Infusoria, are usually Protophytes of various kinds, either entire 

 or in a fragmentary state. The Diatomacese seem to be the ordi- 

 nary food of many ; and the insolubility of their loricce enables 

 the observer to recognize them unmistakably. Sometimes 

 entire Infusoria are observed within the bodies of others not 

 much exceeding them in size (Fig. 199, B) ; but this is only 

 when they have been recently swallowed, since the prey speedily 

 undergoes digestion. It would seem as if these creatures do not 

 feed by any means indiscriminately ; since particular kinds of 

 them are attracted by particular kinds of aliment; the crushed 

 bodies and eggs of Entomostracea, for example, are so vora- 

 ciously consumed by the Goleps, that its body is sometimes quite 

 altered in shape by the distension. This circumstance, however, 

 by no means proves, as some have considered it to do, that such 

 creatures possess a sense of taste and a power of determinate 



Group of Vorticella nebulifera. showing 

 A, the ordinary form; B, the same with the 

 stalk contracted; c, the same with the 

 bell closed; D. E, F, successive stages of 

 fissiparous multiplication. 



