42 HOG CHOLEEA 



diffuse in character. The pharynx and esophagus 

 are rarely affected, the stomach and small intes- 

 tines frequently are, while the mucosa of the 

 cecum and upper colon usually is involved. 



The skin lesions may consist of congestion or 

 hemorrhage of circumscribed or diffuse nature, 

 the latter type being by far the most common, and 

 appearing as a purplish discoloration usually con- 

 fined to the ears, belly, snout, inner surfaces of 

 the legs, tip of tail, vulva, and perineal region. 

 Small skin ulcers less than two centimeters in 

 diameter, irregularly round or oval in shape, 

 brown in color and scabbed over, appear somewhat 

 infrequently on the throat, very exceptionally 

 elsewhere on the body. These seemingly take 

 origin from previous hemorrhages. 



Some have considered all these changes as due 

 to secondary invasion, holding to the belief that 

 hog cholera virus in itself does not produce mac- 

 roscopic lesions. To this view we are unable to 

 subscribe, for one may transport filtered virus 

 hundreds of miles, and it will still produce, regu- 

 larly, some or all of the leions just described, and 

 it is inconceivable that the same secondary in- 

 fluences should be present in all localities. 



In order to place in relief the more character- 

 istic macroscopic lesions which, according to our 

 conception, are due usually to unaided action of 

 the filterable hog cholera virus, we have for the 



