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capillaries, crammed with erytkrocyctes. Tlie submucosa is in progressive 

 stages of inflammatory swelling ; one instantly recognises its being a 

 granulation tissue by its wealth in vessels and its dense network of con- 

 nective tissue. Cavities and fissures filled with plasmatic cells poor in 

 chromatin are situated directly below the muscularis mucosae ; these 

 elements are evidently the overgrown, desquamated, endotheha of the 

 lymph vessels. Small crowds of leucocytes surround blood vessels close 

 to necrotic foci, whilst regeneratory processes are scattered here and there 

 with multiplication of the connective cells and lymphocytes, which last 

 originate from the folhcular apparatus of the intestines as shall be demon- 

 strated later. The centre of the infiammation, namely, the plexus 

 containing lymph vessels between the circular and longitudinal layers of 

 muscles follows this relatively narrow zone ; it is remarkable on- account 

 of the large number of cavities containing fibrine and leucocytes, and 

 measures 1 -2 cm. to 1 -3 cm. in diameter. Directly under the submucosa are 

 irregular groups of muscles and scattered muscle fibres, which can easily 

 be recognised as the remains of the circular muscles ; cavities containing 

 more or less dense endothehal elements as already described form layers 

 around these. In places the epithelial accumulations are so compact that 

 at first sight they have the appearance of carcinomatous infiltration. It 

 is chiefly connective elements which surround in great quantities the large 

 cells in the denser parts ; arteries and veins thickened by connective 

 tissue and encrusted with leucocytes are not rare. Dense tangles of 

 vessels or ramifications of such bring variety into the image. 



Large lymph spaces and emigration phenomena, as found in the 

 subcutis, are seen embedded in fibrine and opposed to the longitudinal 

 musculature. Disregarding their contents, the large round cavities are 

 readily recognised on account of their walls to be lymph vessels. Dense 

 bands of leucocytes follow in waved lines the course of the blood vessels 

 around these lymph spaces. The longitudinal musculature is disrupted, 

 and its fasicles lie in a net-hke tissue, which merges into the thickened 

 serosa. Similar cavities are found in the serosa, only here the tissue 

 immediately surrounding them is more packed with leucocytes and, con- 

 sequently, shows older stages of lymphangitis. The epithelium of the 

 serosa has totally disappeared, fibrinous deposits, in all stages as described 

 for the pleura, have taken its place. 



These observations serve as further proof that pleuro-pneumonia 

 infection follows the course of the lymph vessels. The lymph plexus 

 between the two layers of muscles which is involved in all affections of 

 the intestine, is also here the centrum of the pathological changes. The 

 large protoplasmatic cells can, following Saltykov (Zeitschr. fur Heilkunde, 

 1900), be regarded as descendants of elements belonging to the lymph 

 vessels. As they throw light on problems discussed above, I reserve the 

 special description of them for a future paper. 



