159 



congested, partl}^ as a direct consequence of the blood 

 changes and partly as a mechanical result of heart 

 failure. Associated with this pneumonia we may also 

 find inflammation of the pleura and of the sac 

 which envelopes the heart (pleurisy and pericarditis). 

 Patches of hsemorrhagic staining are frequently seen 

 beneath the serous and mucous membranes, in the 

 coats of the vessels themselves, and in the tissues 

 generally. 



Jaundice is a not infrequent accompaniment, but 

 does not seem to be due to obstruction of the bile 

 ducts, since this is not markedly present. It is con- 

 sidered to be caused by diminished blood pressure, 

 combined perhaps with some slight measure of 

 catarrh in the smaller ducts, leading to the tension in 

 the gall bladder and duct becoming higher than that 

 in the blood vessels, and so causing an absorption of 

 the bile by the blood of the portal (liver) circulation.* 



Under the microscope the bacilli can be seen 

 adhering to the lining membrane of the smallest 

 blood vessels (capillaries), and gradually clumping 

 together so as ultimately to form plugs. These at 

 length completely block up the channel, and so give 

 rise to exudations of blood through the walls of the 

 vessels, forming the minute hsemorrhages which have 

 been mentioned. When as a consequence of this 

 obstruction of the capillaries the bacilli contained in 

 the exuded blood have invaded the tissues themselves, 

 they are thereby at once enabled to multiply and to 

 develop their poisonous products even more freely 

 than when they were exposed to the germicidal action 

 of the phagocytes and of the serum of the circulating 

 blood in the blood vessels. 



As is only to be expected, it always happens 

 that if the illness is prolonged by reason of the 

 patient's relative power of resistance, he becomes 



* Green. Pathology and Morbid Anatomy. 9th edit, page 66. 



