184 CONTAGIOUS DISEASES. 



thelium of the pulmonary vesicles and a catarrhal proliferation of 

 their elements. The virus then penetrates from these vesicles 

 and the smaller bronchi into the neighbouring lymphatics (peri- 

 bronchial lymphatics), but not into those of the bronchi," &c. 

 From this it appears that this author's opinion is that the initial 

 start of the malady is in the bronchioles, and from these to the 

 lymphatics or lymphatic spaces — the perilobular networks. 

 This idea is radically false. Sims Woodhead mistakes the 

 epiphenomena for the primordial phenomena — such as clinical 

 observation shows very distinct. Every practitioner who cares 

 to take the trouble to inform himself otherwise than through 

 his imagination will readily perceive that at the periphery of 

 the hepatised mass there are almost constantly met with, in an 

 extent of 5, 10, 15, and 20 centimetres, connective tissue bands, 

 with their ramifications distended by the exudate of pleuro- 

 pneumonia, without any alteration, any change even . in colour, 

 in the pulmonary lobules, which are surrounded by these 

 advanced-guard projections. When two such projections run 

 parallel at a short distance from each other, we can clearly see, 

 from their point of emergence from the hepatisation, the gradu- 

 ated effects of the compression they exercise on the imprisoned 

 strip of lung. The congestion and density of the lobules is then 

 marked in decreasing proportion from the base to the terminal 

 divergence of the two infiltrated bands (or spaces) ; while, on 

 the contrary, the lobules outside them and touching them 

 remain absolutely healthy. The clinical facts, which are very 

 common, I repeat, prove distinctly that the evolution of con- 

 tagious pleuro-pneumonia takes place from the connective tissue 

 septa (interlobular spaces) towards the pulmonary vesicles, and 

 not — as Sims Woodhead asserts — from the bronchioles towards 

 these septa. The obstruction of the vesicles, the catarrhal and 

 ephithelial transformations, the blood stasis, the pulmonary 

 hepatisation, in a word, are evidently not the initial essence 

 here, but rather physical corollary or epiphenomena. It is in 

 this course, by this order in succession of the pleuro-pneumonia 

 lesions, that in a first case, for instance, the practitioner can 

 most certainly affirm the contagious nature of the malady ; for 

 whatever may be said and written to the contrary, there is 

 observed in the bovine species a non-specific pneumonia and 

 pleurisy, which may or may not be coincident, and the altera- 



