130 DIGESTION OF ANIMALCULES. 



hundred in some species ; in others, they are less 

 numerous. 



It is on the characters and positions of these sacs, 

 and on the course of the presumed intestinal tube, 

 that Ehrenberg has founded the divisions of this 

 class ; but professor Jones, while he acknowledges 

 that the views of this naturalist are sanctioned by 

 general consent, is not disposed to admit their 

 accuracy in all respects, and states that his own 

 observations (made by means of a compound achro- 

 matic microscope, and employing powers nine-tenths, 

 one -half, one-fourth, and one-eighth of an inch 

 focus) have led to very different conclusions. The 

 positions of the orifices for the reception and rejec- 

 tion of aliment he found to be such as Ehrenberg 

 has indicated ; but the most patient investigation 

 did not enable him to detect the arrangement of the 

 tube, and the sacs appended to it, as figured and 

 described by that author. He states that he has 

 never been able to perceive, when one of the car- 

 nivorous animalcules has swallowed another, that it 

 has been conveyed, as was to be expected, into one 

 of these so-called stomachs, but that he has traced it 

 into " what seemed a cavity excavated in the general 

 parenchyma of the body." 



In the next place, he states that these sacs have 

 no appearance of being attached to any tube by 

 means of penducles, or necks ; and that in parame- 

 cium aurelia, so far from appearing to be connected 

 with a central canal, as is represented by Ehrenberg, 



