234 Annals Entomological Society of America [Vol. XIII, 



apparent unity of the structure as viewed externally, together 

 with its likeness to glandular tissue as seen in section accounts 

 for the name "internal gland" applied by other authors. The 

 term is retained here only as a convenient designation and for 

 want of proper name which will suggest its real anatomical or 

 physiological nature. 



The passageway between anterior and posterior crop is small 

 and irregular in outline. Both divisions of the crop are much 

 folded in a longitudinal direction at their point of junction. 

 This makes a narrow, tortuous connection, at least when the 

 two parts are not distended with food. The circular muscles in 

 this region are not well developed so that there does not appear 

 to be any valvular apparatus for the separation of the two 

 cavities. 



The anterior end of the second division of the crop has its 

 walls much folded. These folds are so close to each other that 

 the lumen is a mere irregular slit. The epithelium in this 

 region is not greatly dissimilar to that found in the floor of the 

 anterior crop. The muscles in the walls of the posterior crop 

 are arranged in an inner circular layer which is thin and evenly 

 disposed, and an outer longitudinal layer whose fibres lie in 

 scattered groups close to the circular layer. 



In the anterior portion of the posterior crop the epithelial 

 cells are packed with oval brownish inclusions similar to those 

 found in the ascending intestine, described later. 



In the middle portion of the posterior crop the epithelium 

 thins out to such an extent that it forms the thinnest of lining 

 membranes (Figs. 12 and 13). The cells lose their columnar 

 character and become cuboid or even squamous. Cell boun- 

 daries are indistinct or entirely lacking. The free border of 

 these cells has a striated zone beneath which is a narrow dense 

 layer of granular cytoplasm followed by colorless alveolar sub- 

 stance which is probably made up of small vacuoles filled with 

 fluid. The proximal portions of the cells are filled with a finely 

 granular protoplasm. The muscle layers are not well developed 

 although they may be demonstrated in certain places. 



In the posterior end of the posterior crop the epithelium 

 becomes somewhat thicker, especially so at the point where the 

 ascending intestine connects with it. Here again the cells show 

 the yellow inclusions which look somewhat like oil droplets. 

 These are similar in appearance to those found in the most 

 anterior portion. 



