ENTRANCE AND SPREAD OF BACTERIA 215 



glands may be infected, and also serous sacs in relation to the 

 organs where the primary lesion exists. Second, by natural 

 channels, such as the ureters and the bile ducts, the spread 

 Itrin^ generally associated with an inflammatory condition of the 

 lining i-pithrlium. In this way the kidneys and liver respectively 

 may be infected. Third, by the blood vessels : (a) by a few 

 organisms gaining entrance to the blood from a local lesion, and 



v- 



. 



Kn:. 58. Secondary infection of a glomerulus of kidney by the 

 , staphylococcus aureus, in a case of ulcerative endocarditis. The 

 cocci (stained darkly) are seen plugging the capillaries and also lying 

 free. The glomerulus is much swollen, infiltrated by leucocytes, 

 and partly necrosed. 

 Paraffin section ; stained by Gram's method and Bismarck-brown, x 300. 



settling in a favourable nidus or a damaged tissue, the original 

 path of infection often being obscure; (6) by a septic phlebitis 

 with suppurative softening of the thrombus and resulting em- 

 bolism ; and we may add (c), by a direct extension along a vein, 

 producing a spreading thrombosis and suppuration within the 

 vein. In this way suppuration may spread along the portal vein 

 to the liver from a lesion in the alimentary canal, the condition 

 being known as pylephlebitis suppurativa. 



