INSECTA. 177 



ner on itself, and receiving at its pyloric extremity the ducts 

 of the highly complicated biliary organs ; the small intestine is 

 short, and the colon has three dilatations in passing to the anal 

 aperture ; the biliary vessels are very numerous, and their 

 secreting surface is much increased by the development of in- 

 numerable small caeca from the sides of the large glandular ves- 

 sels ; these two examples sufficiently prove that in the struc- 

 ture of the digestive organs of carnivorous and phytophagous 

 insects a marked difference exists. 



In the orthoptera, the grasshopper for example, the esopha- 

 gus is dilated into a crop, opening into a round muscular 

 stomach, the internal surface of which is armed with horny 

 teeth ; the true chylific stomach succeeds this muscular organ, 

 and is abundantly supplied with minute follicular appendages, 

 and the secreting surface of its internal membrane is greatly 

 increased by being thrown into delicate folds. 



In the neuroptera the stomach and intestinal canal are allied 

 to the preceding ; being nearly all predacious, their masticatory 

 organs are highly developed, and the intestine passes nearly 

 straight through the body. 



Among the hymenoptera the digestive organs of the bee are 

 the most interesting, as, in addition to the functions of nutri- 

 tion, they form two important products, wax and honey. The 

 sucker (fig. 196), leads into a large bag, situated on the anterior 

 part of the esophagus, with which it communicates ; here the 

 nectar obtained from flowers is converted into honey, which 

 the bee disgorges at pleasure into the cells of the honeycomb. 

 The esophagus terminates in a small gizzard, to which suc- 

 ceeds a large sacculated stomach ; into its pyloric portion the 

 biliary vessels enter ; the diameter of the small intestine is 

 inconsiderable, but that of the colon is very ample, the inter- 

 nal membrane of which has a glandular character, probably 

 intended for the secretion of the wax. 



In the hemiptera, the common bug has been examined with 

 great care by Ramdohr ; he found its digestive organs to con- 

 sist of two stomachs, the first being very capacious, and serving 

 as a reservoir for the imbibed juices ; the second being very 

 complicated, and provided with caeca ; to the small intestine 

 succeeds a colon of considerable dimensions, provided with 

 caecal appendages. Connected with the termination of the in- 



