576 THE INTESTINAL CANAL, BY E. KLEIN AND E. VEESON. 



tached from the parenchyma, like the fingers of a glove, and a 

 delicate network then comes into view "between the paren- 

 chyma and the epithelium, the threads of which are continuous 

 now with the former, now with the latter. The appearances 

 presented, however, are essentially due to manipulation. The 

 network is composed of spheroidal cells, and the transition of 

 such free but closely approximated cells into an apparent 

 plexus * may be distinctly followed. 



Whether these spheroids are modified red blood corpuscles, or 

 descendants of the epithelial or of some other cells, cannot be 

 satisfactorily determined. Their appearance, and a comparison 

 of them with red corpuscles altered by means of chromic acid, 

 renders the former opinion the more probable one. In these 

 animals then it is certain that no direct communication exists 

 between the epithelium and the stroma. 



It is more difficult to speak decisively on this point when 

 the epithelium is not detached, since it is frequently requisite 

 to decide whether two fibres lying in close proximity are con- 

 tinuous with each other. 



NERVES. Two thick layers of ganglionic nervous masses 

 are distinguishable in the small intestine, one of which is si- 

 tuated in the tunica submucosa, and the other between the 

 < circular and longitudinal muscular fibre layers. The former, 

 first described by Meissner,* is arranged in the form of a flat 

 layer, although a few ganglia project towards the mucous 

 membrane, and penetrate between the adjoining follicles; the 

 latter, discovered by Auerbach,-[- is more irregular, presenting 

 nodulated ganglionic masses, which are particularly large and 

 numerous where the septa of connective tissue dip into the 

 circular muscular layer. 



The several ganglia may attain a diameter of 0'4 of a milli- 

 meter, and give off and are traversed by nerves varying from 

 O002 to 0'004 of a millimeter in diameter, that form a plexus 

 the branches of which penetrate the circular muscular coat 

 with the septa of connective tissue, and establish a communica- 

 tion between the two ganglionic layers. Other branches pass 



* Zeitschrift fur rationelle Medicin, Band viii., 1857. 

 \ Ueber einen Plexus Myentericus. Breslau, 1862. 



