52 PROCEEDINGS OF THE ACADEMY OF [1881. 



strengthened, I niiobt almost say entirel_y confirmed my opinion.' 

 Some of the results thus obtained will have value to many stu- 

 dents, and they are therefore briefly presented here. Without 

 entering fully into anatomical and histological details, enough will 

 be given to confirm and explain the facts related and opinions 

 stated above. 



The Alimentary or Intestinal Canal. — The whole eoui'se of 

 the alimentary tract from the mouth to the anus was carefully 

 worked out in many dissections. Less attention was given to the 

 head ; the pharynx and mouth parts were, however, worked out. 

 Attention Avas, of course, chiefly directed to the abdomen and con- 

 tents. 



The intestinal canal is composed of the following parts : 



I. Within the head there are : 



§ 1. The mouth and the mouth-parts, viz. : the mandibles (Plate 

 VII, figs. 37, 38) w6.,- which are armed with teeth of irregular size ; 

 the maxillse, mx, and maxillary palps, mx. p ; the labium, Ib.^ and 

 lower lip, the labial palps, lb. p., and the tongue, to. 



§ 2. The buccal sac (fig. 51, 6c.s), a spherical expansion at the 

 anterior part of the pharynx, in the middle of the front part of 

 the head. Its function is not determined.^ It is frequently found 

 filled or partly filled with various, amorphous particles, the debris 

 of food, etc. Brants, who first discovered it in the wasps, supposes 

 that it may serve those insects in the preparation of their paper- 

 nests. Forel conjectures that it may serve the purpose of a special 

 digestion for the anterior part of the body. Lubbock once found 

 in it an entire worm. It would appear to be a sort of anatomical 

 " Botany bay" for the temporary seclusion of such food material 

 as may not be prepared to yield the juices which alone pass into 

 the crop. 



' I mounted many of my preparations for more leisui'ely study under the 

 microscope, and they have been submitted to the Academy of Natural 

 Sciences of Philadelphia. I acknowledge here the assistance and advice 

 of Prof. J. Gibbons Hunt, M. D,, in these studies, whose unrivaled skill 

 as a microscopist was cordially placed at my disposal. 



^ The reference-symbols are uniform in all the figures, and are for the 

 most part such abbreviations of the names of the parts as may aid the 

 memory in studying the plates. See the key to reference symbols. 

 • 2 See Forel Swiss Ants, p. 109 ; Lubbock, Microscop. Jour., London, 

 1877, p. 139 ; Agricultural Ants of Texas, p. 119. 



