52 Annals Entomological Society of America [Vol. Ill, 



more or less regular longitudinal rows of large protruding cells. 

 The whole canal, including the salivary glands and the Mal- 

 pighian tuljules is clearly visible through the larval body wall. 



In the posterior portion of segment 8 the slender ileum arises 

 abruptly from the thick \-entriculus as a cur\-ed and folded tube. 

 Its cellular wall consists of se\-eral rows of large cells distinct in 

 the anterior orange portion, less so in the whitish translucent 

 middle part, and disappearing in the slenderer hinder end. which 

 opens into the delicate grayish colon. The rectum is a rather 

 colourless tube of considerable length terminating in the anus on 

 segment 1 1 . 



The extreme hind part of the canal probably functions but 

 little, except perhaps when the larva is near pupation. It was 

 not seen to" contain any waste matter, and if the larva was 

 submitted to considerable pressure under a coverglass no excre- 

 ment would be discharged. 



Glandular and Excretory Appendages of the Alimentary Canal. 

 The sali\'ary glands are of large size and extend along each side 

 of the ventriculus to the middle of segment 6 where the\' 

 recurve dorsally and proceed to the anterior end of segment 5. 

 being fastened to the ventriculus at that point. The larger 

 posterior portion of the glands are glassy white and of monili- 

 forme asj^ect. with several rows of large glandular cells containing 

 large nuclei. At about the middle of segment 3 the glands 

 become narrower, lose their glassy, large-celled appearance, and 

 twisting spirally downwards, then upwards, dilate abruptly into 

 granular ampullae of a pale yellowish-white color. These are 

 three in number, two larger posterior ones and a single incon- 

 spicuous anterior swelling. From this latter point the glands 

 taper gently, and at about the posterior border of the super- 

 numerary segment give place to the tracheoid ducts. These are 

 short slender tubes and join to form the common duct. B, Fig. 2. 

 PI. VI, a short distance within the chitinous rods of the head 

 skeleton. 



Whether the secretion of the sali\ar\- glands of the larva 

 produces an irritation in the plant tissue thereby causing a fiow 

 of resin, or whether "the twistings of perhaps a dozen spiny- 

 skinned larvae smooth out a round cavity" (in the resin), "the 

 irritation causing a constant supply of fresh resin," to use Eckel's 

 own words as regards C. resinicola, is a difficult thing to determine. 

 Giard (9) thinks that the "zymase" secreted by the salivary 



