104? INTERNAL ANATOMY OF INSECTS. 



the size of its different parts, in the number and form of 

 its dilatations, and particularly of its stomachs and its 

 ccecums, and in the folds of its interior exhibits varia- 

 tions altogether analogous to those of vertebrate animals, 

 and which produce similar effects a . As to its parts, it 

 may be considered as consisting of two larger portions, 

 between which the biHary or hepatic vessels form the 

 point of separation. In the first, the most universal parts 

 are the gullet and the stomach ; and in the second, the 

 small intestine and the large intestine b . 



1. The gullet ((Esophagus*) is that portion of the in- 

 testinal canal which, receiving the food from the pharynx, 

 or immediately from the mouth, conveys it to the sto- 

 mach. Though it often ends just behind the head d , it 

 is usually continued through the trunk, and sometimes 

 even extends into the middle of the abdomen* ; it there- 

 fore seldom much exceeds in length half the body. It 

 is constantly long when the head is connected with the 

 trunk by a narrow canal as in the Hymenoptera, Neu- 

 roptera, Lepidoptera, &c. ; but is frequently short when 

 these parts are more intimately united f . It often ends 

 in a kind of sac analogous to the crop of birds. Un- 

 der this head I must mention a part discovered by 

 Ramdohr, which he calls the food-bag (Speisesack), as 

 he thinks, peculiar to Diptcra%. From the mouth in 

 these proceeds a narrow tube into the abdomen, where 



a Cuv. ubi supr. 113. b Comp. Ramdohr Anat. 7. 



PLATE XXI. FIG. 3. c. 



d Tenebrio Raradohr, ubi supr. 9. /. iv./. 1. 



e Agrion. Ibid. t. xv./. 4. a, b. * Ibid. 



2 Many other insects that live by suction have something similar, 

 as the honey-bag of butterflies, PLATE XXX. FIG. 10, 11. a. Ram- 

 dohr /, xviii./. 2. with /. xix./. 1 3. and xxi. 1, 3. &c. 



