Dr. Meyen on the Digestive Apparatus of Infusoria. 101 



paper was sent as early as October to Prof. J. von Muller for 

 insertion in his i Archiv,' and since then I have seen in your 

 journal that Prof. Rymer Jones has made some correct ob- 

 servations on the same subject, which have been controverted, 

 but unsuccessfully, by Prof. Ehrenberg. 



[We gladly comply with the wishes of our learned corre- 

 spondent, and, in order to lay the whole subject as it at pre- 

 sent stands before our readers, we have extracted from the 

 elegant and valuable work of Rymer Jones the passage treat- 

 ing on this subject. We intend also to give in our next num- 

 ber an extract from a memoir which has recently been pub- 

 lished by M. Dujardin in the 'Annales des Sciences Natu- 

 relles/ which is likewise opposed to the views taken by Dr. 

 Ehrenberg. In the mean time we hope that some of our 

 English naturalists (excellent microscopes being now much in 

 use in this country) will take up this subject and help to 

 bring this interesting question to an issue. — R. T.] 



It will be well known to naturalists that Von Gleichen even 

 as early as the year 1781 fed the infusorial animalcules with 

 carmine, and observed on the following day that several red 

 globules were apparent in the interior of their body, whence 

 he drew the inference that the animalcules had swallowed the 

 colouring substance ; Gleichen also observed that the coloured 

 globules were expelled by a distinct aperture. Gleichen figures 

 these received red globules very correctly, and indeed each 

 globule in the interior of a distinct circle, without stating any- 

 thing respecting their design. Subsequently Prof. Ehrenberg 

 repeated these observations, and thence concluded that the 

 true Infusoria possess a larger or smaller number of stomachs, 

 which in one group are destitute of intestinal canal, but in the 

 other are connected with one another by peculiar extremities 

 of the canal, nay sometimes exhibit laterally appended canals 

 en cul-de-sac. In consequence of these discoveries the ani- 

 malcules received the name of Polygastrica. M. Ehrenberg 

 thought he observed that these stomachs are filled in regular 

 succession, and he has even figured, more or less completely, 

 in a number of animalcules of this kind, the intestinal canals 



