iM::\rARKAiu,i: spfciks of Kcimnoins. .>,] 



i\\ct thnt it is at most places more than one cell in thickness, 

 and secondly by the relatively bnlky component cells containin<>; 

 an abundance of variously sized spherules of a yellowish brown 

 color. Those cells [jr (/»'.)], which sit with one end directly on 

 the subjacent connective-tissue, aie of an oblong or elongate shape 

 and possess round nucleus with distinct chromatic bodies, while 

 the others \_b (p)'.)^ more superficially situated are shorter, being 

 roundish or irregular in shape, and show clear looking nucleus 

 with only a few and indistinct chromatic bodies. Some of the 

 latter kind of the colls detach themselves from the peritoneal 

 surface and fall into the cœlomic cavity. Evidences of this fact 

 can be easily obtained by tracing on serial sections. The cells 

 thus liberated can impossibly be distinguished from the corpuscles 

 {b.c.) found floating in the cœlomic fluid. In fact I take no 

 heed in regarding the region in question of the ventral mesentery 

 to be the formative source of all the cœlomic corpuscles. 



Passing on to the midgut, T find that the small transverse 

 folds on the internal surface are formations of the lining epithel- 

 ium alone (fig. 40, epl.). They are made up of spindle-shaped 

 or pyramidal epithelial cells arranged in several layers with tlieii* 

 long axis directed nearly vertical to the epithelial base ; whereas 

 at the bottom of the narrow^ depressions between the folds, the 

 epithelium consists of comparatively short cylindrical cells in a 

 single layer. Near the free internal surface of the folds are 

 some small unicellular glands (gl.) of a flask-like shape, opening 

 by narrow duct into the gut lumen. Close to the base of the 

 epithelium is the layer of longitudinal muscle fibers {I.m.). That 

 of circular muscle fibers (cm.) lies more externally and close 

 under the peritoneum {pr.). This is composed of cells which 



