162 OMENTAL PLAGUE chap. 



the mesenteric glands were preserved in Muller's fluid 

 with a view to afterwards making sections. 



On examination, the stained and mounted sections of 

 the intestinal haemorrhagic patches and Peyer's glands, as 

 also sections of the mesenteric glands, showed in both 

 cases (Eat 1 and Eat 2) the same condition. It will 

 suffice therefore to describe the appearances in one animal 

 only. 



Eat 1 — the appearances are shown in Figs. 75, 76, 

 and 77. Fig. 75 shows a transverse section of the swollen 

 Peyer's gland with margin of surrounding tissue, under 

 low magnification ( x 25). As is well seen, the Peyer's 

 gland projects considerably on the serous (peritoneal) 

 surface, and opposite this projection — i.e. towards the 

 cavity of the intestine — is a mass of debris extending over 

 the surface of the mucous membrane beyond. Under a 

 high power masses of bipolar-stained B. pestis are recog- 

 nisable in this debris as small and large clumps ; they 

 appear as dark stained patches. In some places, e.g. in 

 the neighbourhood of line 1, a large mass of B. pestis 

 may be seen embedded in finely granular material, which 

 is in fact a remnant of one of the original colonies in the 

 agar with which the animal had been fed. The superficial 

 part of the Peyer's gland — below the central mass 1 — is 

 necrotic tissue with a large amount of diffused blood. At 

 5, the mucous membrane (villi) is devoid of its surface 

 epithelium ; its mucosa shows numerous vessels distended 

 by blood, and in its tissue is effused blood ; so also around 

 the crypts there is a good deal of effused blood. Masses 

 of B. pestis are seen not only everywhere between the 

 tissue elements of the villi, but also in the effused blood. 

 At 2 and 3 in the space between swollen lymph follicles, 



