PLEURO-PNEUMONIA. 187 



to get the section to you in as fresh a state as possible. When you 

 saw the section I remember distinctly that it was quite fresh and free 

 from any signs of putrefaction. If I can be of any assistance to you 

 in this case, please command me. With many happy returns of the 

 past holiday season to you and yours, — Very respectfully, 



"W. H. Wray." 



Now, in conclusion, I have simply to say that the American 

 disease is not pleuro, but that it agrees in every respect with 

 what Gamgee, Billings, and Nocard have described as broncho- 

 pneumonia, and that it is identical — but the specimens show a 

 more chronically diseased condition — with what I discovered iii 

 both States and Canadian cattle landed in Liverpool in 1879. 



One other observation. I trust that this controversy will 

 lead to good results ; that veterinary surgeons will in future 

 have greater faith in microscopic investigations, as by such 

 methods it has been proved that pleuro-pneumonia is a disease 

 commencing in the perilobular tissue, and that catarrhal or 

 broncho pneumonia proceeds from the tubes and air cells, from 

 which pus can be pressed out, and that its best result is seen to 

 be a desquamation of the epithelium of the inflamed tubes ; that 

 in pleuro fibrin is exuded in abundance into the connective 

 tissue, air vesicles, bronchioles, and blood-vessels, where it co- 

 agulates into permanent clots ; that pus is seldom or never 

 found, and that in broncho-pneumonia more or less purulent 

 matter is found, and the remarkable exudation of fibrin into the 

 vessels, bronchi, and pulmonary tissue is notable by its absence. 



In October 1892 pleuro-pneumonia was reported to have 

 been detected in Canadian cattle bought at Dundee. This out- 

 break has given rise to another difference of opinion, and up to 

 the date of going to press the veterinary officers of the Board 

 of Agriculture maintain the correctness of their opinion. The 

 coloured drawing, page 176, is an exact reproduction of the 

 niiscroscopic appearance of a portion of the lung in dispute. 



