INFUSORIAL ANIMALCULES. 43 



may even be counted. But that this alimentary canal does not, after 

 a short course, terminate abruptly in the body, can also be proved in 

 the Epistylis grandt's." 



" In this animalcule, a portion of coloiu-ing matter swallowed, is 

 seen to course along an intestine, and enter a ceU. I also once atten- 

 tively observed, what appeared to be the extremity of the intestinal 

 canal, to ascertain what the further coui'se of the coloiu-ed particles 

 would be. At this time the animal had not filled any of the cells in 

 its inside ; suddenly two lateral cells became filled, although I did 

 not perceive any nutriment pass along the common tube. This 

 clearly points out that the two cells must be in connexion with the 

 common cavity, from which they had become fiUed, and when, after 

 the animal has fed for a considerable time, we see that similar filled 

 cells are diffused thi'oughout the body, this phenomena affords a 

 groimd for the supposition that the intestinal cavity is of greater 

 length than we should at first sight imagine." (Wiegmann's 

 Ai'cliives, 1846, translated in Annals v. xviii, p. 433). 



Since the above was written, we have met with the opinions of 

 Professors "Wagner and Yan der Hoeven, as expressed in their recent 

 works: (Wagner's " Zootomie," 1848, Sect. Infusoria; and Van der 

 Hoeven's "Lehbuch der Zoologie," 1850). Wagner aflirms that, 

 " by an examination, however close, no one can convince himself of 

 the actual existence of such an organization as Ehrenberg affiiTns." 

 Like Siebold, he describes the derivation or formation of the vacuolse 

 (stomach-sacs, SJ7i.) from without, but differs from that observer in 

 not regarding their production as a consequence of the primary in- 

 troduction of water. 



"With Van der Hoeven, all coincide in denying the existence of an 

 enclosing wall to the vesicles, and of an intercommunicating tube 

 between them ; and aU assert the ever-varpng number and disposi- 

 tion, as well as the movements (even rotatory) of these supposed 

 stomachs. In the course of argument, "Wagner says, that " in many 

 Infusoria, where larger bodies, such as I^Taviculae or joints of Algae, 

 have been swallowed, no surrounding vesicle or sac is \-isible ;" and 

 these large bodies will sometimes occupy the entire length or breadth 

 of an animalcule. Where no mouth is visible, nutrition is carried on 

 by the general siu'face. 



