ORGANS OF DIGESTION. 63 



chew the cud. The chewing motion which deceived 

 them, I have found to be the process of cleaning the 

 feet and the ears. The gizzard is not found in all 

 insects. 



The stomach^) is composed of thin, soft, extensible, 

 membranes, usually cylindrical in form, but some- 

 times with bulgings and contractions, and sometimes 

 forked, the entrance ( 2 ) being at one of the forks. One 

 remarkable circumstance is, that, in many insects, the 

 outer surface is covered with a number of teat-like 

 points, similar to the finger of a glove, containing 

 fluid which they discharge into the stomach. These 

 may be termed vessels ( 3 ). They vary much in size 

 and number, and are not found in all insects. Dif- 

 ferent opinions are held respecting them by Cuvier, 

 Marcel de Serres, and Leon Dufour. 



In all insects, we believe, there are vessels called 

 bile vessels ( 4 ), consisting of several membranous tubes, 

 filled with a peculiar fluid, bitter, and usually brown 

 or yellow, but sometimes limpid, supposed to be 

 similar to bile, though we find nothing like the liver 

 for preparing this bile, which is probably, therefore, 

 as M. Gae'de thinks, prepared in the vessels them- 

 selves. These vessels float in many convulutions in 

 the abdomen, one end being sometimes free and the 

 other fixed, and sometimes both ends fixed, and 

 giving rise to a sort of arch or curve. Sometimes 

 these are inserted into the stomach near its outlet ( 5 ) ; 

 in others, one end goes into the stomach, and the 

 other into the blind gut. Their number varies from 

 two, which are found in the rose-chafer, to four, 

 found in beetles and common flies ; to six, found in 

 butterflies, and to even one hundred and fifty (pro- 



(1) In Latin, Ventriculus chyliftcus, or Duodenum. 



(2) In Latin, Cardia. (3) In Latin, Villi. 



(4) In Latin, Vesiculi biliarii. (5) In Latin, Pylorus. 



