4 Illinois State Laboratory of Natiiral History. 



spherical cells, similar to those of the gastric epithelium, 

 and like them usually binucleate, but containing more 

 fatty granules. These cells are variable in size, and in- 

 dividual ones become greatly swollen, and probabW break 

 down in secretion. The lumen of the tube is an irregu- 

 lar linear space, not always readily distinguishable in 

 the midst of the cells. That these tubules actualh^ com- 

 nmnicate with the intestine at the point of their inser- 

 tion, I have repeatedly demonstrated under the micro- 

 scope by carefully readjusted pressure on the cover-glass. 

 By this means granules may be made to pass freely from 

 any one of the coeca into the intestine, and even from the 

 third stomach into the coeca through the slender portion 

 of the intestine connecting them. 



The microbe of these cceca (in the chinch bug commonly 

 Micrococcus'^ insectoruni only) occurs primarily in the inter- 

 cellular fluids of these structures, and was excessively 

 abundant in every one of a great number of specimens, 

 the coeca of which I examined separately. My specimens 

 were from all parts of the State of Illinois and from 

 Kansas, and were of various ages, from young immedi- 

 ately following the first moult to the adult. A thorough 

 exploration and examination of all the other organs of 

 these chinch bugs failed to discover any trace of this or 

 any other bacterium, with the exception of an occasional 

 infection of that part of the intestine into which the 

 coeca o))eu. 



Exam])les of five other genera of Lygfeidae have thus 

 far been dissected by us, in three of which {Lygceus tur- 

 cicus, Nysius angustatus^ a/ad Geocoris uUginosus) there is 

 no trace of these "pancreatic" organs, while in two oth- 

 ers {Trapezonotus nebiilosus, and Myodocha serripes) they 

 are present in a stage of development quite above that 

 of the chinch bug, but far below that characteristic of 

 the higher Hemiptera. In Myodocha, for example, they 

 are made up of numerous coecal tubes arranged side by 

 side in a single layer, in flat, leaf-like lobes, three in suc- 

 cession, the largest leaf anterior, and the middle one of 

 the series the smallest, the three being bunched together. 



