Scientific Jntelligence — Zoology. 381 



vesicles, and, finally, their expulsion in the state of excrements ; 

 there, also, one might count the contractions of the vesicles intended 

 for circulation, and determine the intervals by measuring the ex- 

 tent. 



The following particulars, says M. Pouchet, are what I have dis- 

 tinctly observed up to the present time ; and they are points, I be- 

 lieve, respecting which no serious objections can be afterwards en- 

 tertained. 



1^^, In the Infusoria, named Polygastric by M. Ehrenberg, there 

 evidently exist vesicular stomachs more or less numerous. 



Id, The number and diameter of these stomachs is fixed in each 

 species that has attained its full development. 



3c?, In the Vorticelli, from 30 to 40 vesicular stomachs can be 

 counted, from 0*008 to 0*010 of a millimetre in diameter, when 

 they ai-e filled with food. In the Kolpodes, there are always from 

 20 to 30 vesicular stomachs of O'OIO of a millimetre in diameter 

 when filled. 



4i/i, The gastric vesicles never run into one another when they 

 come in contact. It is easy to perceive that they have distinct walls. 

 The alleged rotation of these stomachs is a curious optical illusion. 

 Tlieso organs are fixed in their respective region, and never remove 

 from it but in respect to the elasticity of their tissue. 



5iA, The aliment does not form a bolus swallowed at once, and 

 producing by chance vacuities in the tissue of the animalcule ; on 

 the contrary, it is introduced gradually. It is seen at first to fill 

 partially each of the gastric vesicles, and then to occupy them en- 

 tirely. 



6^A, The contractile vesicles of the Microzoa are true circulatory 

 organs, representing the single or multiple heart of the higher ani- 

 mals. It is impossible to regard them as respiratory or genital 

 organs, as some naturalists have done. 



7^/t, These contractile or cardiac vesicles are usually single, and 

 contain a fluid analogous to blood, presenting a texture of a clear ful- 

 vous yellow, which renders it easy to distinguish them. 



8M, In the Vorticelli, the cardiac vesicle is single, and acquires 

 an enormous volume compared with that of the animalcules. In 

 Vorticelli of 0'080 of a millimetre in diameter in length, it attains 

 to 020 of a millimetre in diameter when fully dilated. It appears 

 also that in these Microzoa it has distinct walls, and that it ter- 

 minates anteriorly in a yellowish conduit. In the Kolpodes, the 

 cardiac vesicle is likewise single, but proportionally smaller ; it is 

 0*015 of a millimetre in diameter in individuals O'lO of a millime- 

 tre in breadth. In the Glauconus, it is only O'OIO of a millimetre 

 in diameter. In the Dileptes, there are two cardiac vesicles which 

 contract successively, one at the posterior extremity of the body, the 

 other towards the centre. 



9«A, In the Vorticelli, the cardiac vesicle fills very slowly, and 

 empties itself only at long intervals, but suddenly. It contracts 



