442 M. Eckhard on the Organization 



which accumulates in the individual cells only, and is here ap- 

 plied to nutrition. Its physiological use therefore is merely as 

 an oesophagus, the separate cells performing the functions of 

 stomach and intestine. The substances return from the gastric 

 cells into the common cavity, travelling from one cell to the 

 other, and are finally evacuated by the anus. These intestinal 

 phenomena cannot all be directly observed, so perfectly as we have 

 just traced them, at one time and in a single individual, because 

 they are of a delicate transparent structure and of the same re- 

 fractive power as the parenchyma of the body ; separate observa- 

 tions however compel us to adopt this view. 



a. In such forms as are not too minute, we can distinctly ob- 

 serve how the nutriment or articles of food artificially supplied, 

 constantly take a definite course in the body ; in some instances 

 the first portion of the alimentary canal can be observed when 

 not in action, as in Epistylis grandis ; it is then frequently seen 

 to be covered on the inner surface with cilia, and which in the 

 Opercularia may even be counted. 



b. But that the alimentary canal, the commencement of which, 

 as just stated, is distinctly perceptible, does not extend through 

 a limited extent only of the body and then terminate, can also 

 be proved in Epistylis grandis. If this animalcule takes colour- 

 ing matters, we perceive that when these have passed through 

 the course of the intestine, which can also be seen when the ani- 

 mal does not eat, a large piece frequently pursues its course for 

 some distance and then only enters a cell. 



c. In the same animal I once attentively observed what ap- 

 peared to be the extremity of the intestinal canal, fig. 6 r, to 

 ascertain what the further course of the coloured particles would 

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

 its inside; suddenly both i i were so, although I had not perceived 

 any nutriment pass by r. This clearly points out that the two 

 cells must be in connexion with the common cavity from which 

 they had become filled ; and when, after the animal has fed for 

 a considerable time, we see that similar filled cells are diffused 

 throughout the body, this phenomenon affords a ground for the 

 supposition that the intestinal cavity is of greater length than we 

 should at first sight imagine. 



3) Anus. — In by far the greater number of cases the absorbed 

 substances are ejected by a distinct aperture. In a great many 

 it has been directly observed, and in these is sometimes placed 

 at that extremity opposite to the mouth, at others near to or at 

 the side of it ; whilst in others we can often conclude as to its 

 presence by a distinctly defined spot. 



I believe that the above observations are sufficient to prove 

 the correctness of the view I have taken of the intestinal canal of 



