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would be difficult to conceive that the alimentary paste wai 

 obliged to separate into thirty or forty portions, in order to be 

 better elaborated. 



These facts seem to prove, therefore, that those organs can by 

 110 means be as.similated to stomachs, being far from fulfilling their 

 iunctions : the abundant humour which they contain induces a 

 supposition that they are a kind of vesicles destined to secrete 

 a species of bile, which supplies the place of the bile in insects, 

 the pancreatic juice, and even the saliva which we observe in 

 animals of a superior order. The small vessels which exist at 

 the upper extremity of these vesicles, would have no other use 

 than to pump up the humour which bathes all the parts of the 

 bodies of iu'-rects, and thus to collect the materials of the fluid 

 secreted in these bili;iry vesicle?. 



The author then proceeds to dotail a variety of interesting 

 experiments in illustraticm of his ideas. By putting these vessels 

 into coloured fluids, without allowing the biliary vesicles to re- 

 ceive any impression from tliem, he saw the vessels absorb the 

 liquor in which they were plunged, and after a certain time the 

 vesicles themselves received the colour. It still remained to 

 ascertain how the secretion of the bile took place when these 

 small vessels no longer existed. In order to verify this point, the 

 author put the hepatic organs in coloured liquors, and he saw 

 that the absorption equally took place by the membranes of 

 these same viscera. Thus, whether the vesicles have or have not 

 secretory vessels, they nevertheless suck up from the humour 

 which bathes all the parts of the body, the materials of their 

 secretions. What also proves that these organs do not in any 

 way perform the functions of the stomach, is, that we frequently 

 observe them filled with an abundant humour in individuals which 

 have died after a long fast. In short, according to M. de Serres, 

 the true use of these pouches cannot ije mistaken, since the indi- 

 viduals who undergo a complete fast perisji the more speedily, 

 the more considerable the qu;intity of the biiiary humour. The 

 bile being, as is well known, an irritating hunicur, its action is 

 most energetic on the membranes of the stomach when it acts 

 upon them in a more direct maimer. 



But M. de Serres does not confine himself to making us ac- 

 quainted with the uses of the various parts of the intestinal canal 

 of insect?: he also gives an anatomical description of this canal, 

 considered in the greater number of families. He has also given 

 us some very valuable details on the structure of this canal, on 

 the membranes of which it is composed, and finally upon the 

 nerves and traches which proceed to it. When an opportunity 

 offers of drawing general conclusions, he does not neglect it. 

 He remarks for instance, that the extent of the tongue and thei 

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