238 



The widest lumen of the ingluvies is in the neighborhood 

 of the first abdominal segment. A powerful muscular complex 

 forms the proventriculus, and consists of eight flesh-colored 

 fascicles, a little over 2 mm. long, convex outside and concave 

 inside at the base. The broader bases of the fascicles are 

 closely fitted to the proventriculus, and their pointed ends are 

 turned backward. Two of these eight fascicles are connate, 

 exhibiting a deep longitudinal fold at their connection. Each 

 fascicle terminates in a chitinous tooth, and the entire complex 

 is covered with tooth-shaped excrescences, or aciculi, directed 

 backward and outward. The same apparatus exists in Omus 

 and in many other insects.^ In the larva of Corethra, a 

 dipteron, these spines are directed toward the lumen of the 

 pharyngeal bulb, forming a sort of weir-basket, and the mech- 

 anism as well as the function of this apparatus must be different 

 from that of the complex in Amblychila. 



Just behind the proventricular apparatus three pairs of Mal- 

 pighian vessels discharge their contents into the very narrow 

 and compactly muscular chylific ventricle. They are of con- 

 siderable length, winding themselves through the lobes of the 

 corpus adiposum, but are not in any way extraordinary, having 

 the histological structure of Malpighian vessels in other insects. 

 Four other short, yellow sheaths, or utricular organs, also dis- 

 charge into the chylific ventricle. Their envelope shows very 

 fine, transverse lines, which do not, under high magnifying 

 power, prove to be ring-muscles. The contents of these 

 sheaths is an aggregation of closely packed, glandular lobules. 

 I assume them to be functionally the so-called pyloric append- 

 ages. They neither precede nor follow the Malpighian vessels 

 but are closely intermingled with the latter, and only with 

 difficulty can be traced to their insertion. 



The anterior portion of the chylific ventricle, connected with 

 the Malpighian vessels and pyloric appendages, consists of a 

 thickened external layer of fine fibrous network with large 

 meshes, having from three to six yellowish glandular lobes en- 

 closed in each mesh. (Fig. 8 a and 5.) The anterior part of 



1 Burmeister: Handbook of entomology, translated by Shnckard. 1836. 



