118 INTERNAL ANATOMY OF INSECTS. 



The next suctorious Order is the Lepidoptera : in 

 these the gullet is long and slender, surrounded at the 

 beginning with a loose transparent skin, and at the base 

 furnished with a pair of lateral sacs, forming the honey- 

 stomach, and probably analogous to the food-reservoirs 

 of the Diptera, which when blown up are of an oval 

 form ; the stomach, as In the bugs, consists of two por- 

 tions, the first being the longest a . There are three free 

 bile-vessels on each side, proceeding from a single 

 branch b . It will not be uninteresting here to abstract 

 from Herold the progressive changes which take place 

 in the intestinal canal in this Order, during the transition 

 of the animal from the larva to the imago state. In the 

 larva, the gullet, the small intestine, and the rectum, are 

 short and thick c , there are a pair of silk reservoirs (se- 

 ricteria), as well as vessels for the secretion of saliva 

 (sialisteria] : if you examine it two days after its first 

 change, you will find the gullet and the small intestine 

 much lengthened and become very slender ; the stomach 

 contracted both in length and size; the rectum also 

 changed, and the silk vessels contracted (1 . These in a 

 pupa eight days old have wholly disappeared ; the gullet 

 is become still longer, its base is dilated into a crop or 

 food-reservoir ; the stomach is still more contracted, and 

 instead of a cylinder represents a spindle ; the small in- 

 testine also is lengthened e : at a still more advanced pe- 

 riod, when it is near appearing under its last form, the 

 gullet and small intestine are still more drawn out ; and 

 the honey-bag, though very minute, has become a lateral 



3 Ramdohr t. xviii./. 1. F, G. b Ibid. L, K. 



c PLATE XXX. FIG. 7. d Ibid. FIG. 8. 



e Ibick FIG. 9. 



