M. F. Dujardin on the Digestive Organs of Infusoria. 17-3 



to indicate a trace? But, as I have before stated, the differ- 

 ence between the two types is so great that this analogy is one 

 of the most imperfect ; and while denying the existence of an 

 intestine in the true Infusoria, 1 admit in the Rotatoria not 

 only an intestine, but even true jaws, respiratory organs, 

 glands and an ovary. 



Can it be said, that it suffices to have demonstrated that the 

 alimentary substances have penetrated from outwards into 

 these vesicles, to conclude, first, that they are stomachs, and 

 then that these stomachs must communicate with an intestine ? 

 for it would not be possible to conceive stomachs having no 

 communication with the exterior. But that is precisely what 

 might be contested ; for this consequence is founded on a false 

 analogy with higher animals, in which the stomach is always 

 in continuation with the intestine. But before coming to 

 direct proofs, we must examine one objection which was first 

 advanced by M. Bory de St. Vincent in 1832, was reproduced 

 in 1835 by Dr. Foeke, of Bremen*, and has recently been 

 again presented to M. Ehrenberg, by Prof. Rymer Jones, be- 

 fore the British Association at Newcastle. This objection, 

 which I consider well-founded, rests on the inner motion of 

 the globules or sacculi, which can in no way be reconciled 

 with the hypothesis of an intestine connecting all these glo- 

 bules together, and which, on the contrary, proves their entire 

 independence. As M. Bory observed, the intestines, the tubes 

 of communication, did they exist, would soon become inextri- 

 cably entangled, unless by supposing them to be indefinitely 

 extensible, they would not allow of the globules moving about 

 as they do in the interior. 



To these objections, founded on the displacement of the 

 pretended stomachs in the interior of the Infusoria, M. Ehren- 

 berg answers in his great work, that this motion is merely an 

 apparent displacement, analogous to that of the small painted 



* The analysis of the communication made by Dr. Foeke to the Associa- 

 tion of German Naturalists at Bonn in 1835, will be found in the Isis for 

 1836, p. 785. M. Foeke says he had never been able to distinguish the sup- 

 posed intestine in Stentor Midleri, in Loxodes bursar/a, and in a species of 

 Vagin%eola\ and declares that the evident motion of the nutriment or of the 

 colour in the interior of the body of these animalcules is incompatible with 

 the supposition of the existence of an intestine. (Hier muss also elne andere 

 (J/ijanizafion des Darmcanals, als die von Ehrenberg angegebene,stattfinden.) 



