PRIMARY DIVISIONS OF THE DIGESTIVE CANAL 299 



insect; i.e., the fore-intestine (stomodceum of the embryo), mid-intes- 

 tine or " chyle-stomach," and hind-intestine or proctodwu-m (Fig. 300). 



Wfe^-: _jg^ 



-n--,-- 



5 primary divisions of the alimentary canal of an < 



FIG. 300. The three primary divisions of the alimentary canal of an embryonic orthopterous 

 insect : br, brain ; isbg, suboesophageal ganglion ; tig, nervous cord ; at, stomodifiim ; -j>>; procto- 

 da?um ; mr, inalphigian tubes; mem-n, mid-intestine; hi, heart; md, mandibles; nix, Mia-', 1st 

 and 2d maxillae. After Ayers, with some changes. 



The three primary regions, with their differentiations, may be tabu- 

 lated thus : 



Fore-intestine (Stomodeeum). Mouth and pharynx. 



Pumping apparatus of Hemiptera, 



Lepidoptera, and Diptera. 

 (Esophagus. 

 Crop or ingluvies, food reservoir, or 



"sucking stomach." 

 Proventriculus. 

 Mid-intestine (Mesenteron). Mid-intestine, " chylific stomach," or 



ventriculus (with coecal glands). 

 Hind-intestine (Proctodseum). Ileuni, or short intestine (with the 



urinary tubes). 

 Long intestine. 

 Colon. 



Rectum (with rectal glands). 

 Anus (with anal glands). 



The appendages of the alimentary canal are : (1) the salivary and 

 poison glands, which arise from the stomodeeum in embryonic life ; 



FIG. 298. Internal anatomy of Jfeta/idj/l//n femur-rubrum : at, antenna and nerve leading 

 to it from the "brain" or supra-oi-sophageal ganglion (*/>); oo, ocelli, anterior and vertical ones, 

 with ocellar nerves leading to them from the brain ; ce, oesophagus ; m, mouth ; lb, labium or under 

 lip; if, int'ra-crsophageal ganglion, sending three pairs of nerves to the mandibles, maxilla-, and 

 labium respectively (not clearly shown in the engraving) ; .w?, sympathetic or vagus nerve, starting 

 from a ganglion resting above the oesophagus, and connecting with another ganglion u</> in-ar the 

 hinder end of the crop; sal, salivary glands (the termination of the salivary duct not clearly 

 shown by the engraver 1 ); nv, nervous cord and ganglia; or, ovary: ur. origin of urinary tubes; 

 art, oviduct; $b, sebaceous gland; be, bursa copulatrix ; ort, site of opening of the oviduct (the 

 left oviduct cut away) ; 1-10, abdominal segments. The other organs labelled in full. Drawn from 

 his original dissections by Mr. Edward Burgess. 



FIG. 299. Digestive canal of Anabrns : m, mouth: OB, oesophagus; sm, the sympathetic 

 nerve passing along the crop ; /, tongue ; frj, frontal ganglion ; br, brain, the nervous cord passing 

 backward from it; sr, salivary reservoir; g, salivary gland; pv, proventriculus ; in; origin of 

 urinary tubes ; ab, sebaceous gland ; 1-10, the ten abdominal segments. Burgess del. 



