144 



tlie v^essel to the outer aspect of the condensation in every direction 

 measures about 150 f*-* 



Fibrine tinction gives results which are so characteristic that it is 

 impossible to make a mistake in the diagnosis. All kinds of changes can 

 take place in the lymph vessels, independent of the typical lesions ; these 

 changes can present themselves as lymphothrombosis, or lymphangoitis 

 haemorrJiagica ; in the last case the vessels contain thrombus rich in 

 fibrine and erythrocytes. If such strictures of lymph vessels take place 

 in peribronchial tissue, the capillaries and bronchioles become obstructed 

 by thenq, and all the lesions of a bronchiolitis sero-fibrinosa appear in 

 the latter. 



The incrustations of fibrine around the blood vessels can be replaced 

 in later stages by thick fibrillae of connective tissue ; this, however, does 

 not seem to occur frequently. More usually dense crowds of leucocytes 

 take the place of the fibrine, which in turn undergo regressive metamor- 

 phoses : karyorhexis, karyolysis, and protoplasmolysis change the whole 

 finely granular mass into untingable flakes of granules, which are in part 

 resorbed and carried away by emigrant leucocytes, and a regenerative 

 process sets in, by which the defect is replaced by fibrillae of connective 

 tissue. 



Should a portion remain behind as detritus, it fills fissure between 

 the sequester formed as just described and the surrounding layer of 

 connective tissue. The connective tissue of the capsule usually merges 

 into that of the interstities ; in the immediate vicinity of the sequesters 

 the characteristic alterations of the lymph vessels with the typical incrus- 

 tations of fibrine are however demonstrable. 



Such conditions appear regularly in chronic cases of pleuro- 

 pneumonia, and in the light of what has been said already can well serve 

 as basis for diagnosis. 



The walls of the lymph vessels merit special attention, for we have 

 to decide whether we have to do with a lymphangitis or not. This 

 question is the more important, as Csokor is of the opinion that it is a 

 productive meso and periarteriitis of the capillaries of the interstitial tissue, 

 of which the enormous stasis in the lymphatic vessels is a consequence. 

 Perfectly fresh foci from the lungs would be most suitable for the study 

 of this problem ; but as such stages are rare we are obliged to have 

 recoui'se to foci derived from other tissues, and to make our deductions 

 by comparative anatomical methods. 



I had the good fortune to find a perfectly recent focus in one speci- 

 men, it being a dilation of a lymphatic capillary. Close beside one sees 

 in the lumina of the vessels shght exudation and coagulation together 

 with strong imbibition and enlargement of endothelial cells. The walls 



*u Mikron, 



