218 INFLAMMATION AND SUPPURATION 



infection. The entrance of the organisms into the blood stream 

 from the lesion of the bone is especially favoured by the 

 arrangement of the veins in the bone and marrow. 



Experimental. — Multiple abscesses in the bones and under the peri- 

 osteum may occur in simple intravenous injection of the pyogenic cocci 

 into the blood, and are especially liable to be formed when young 

 animals are used. These abscesses are of small size, and do not spread 

 in the same way as in the natural disease in the human subject. 



In experiments on healthy animals, however, the conditions are not 

 analogous to those of the natural disease. We must presume that in the 

 latter there is some local weakness or susceptibility, which enables the 

 few organisms which have reached the part by the blood to settle and 

 multiply. Moreover, if a bone be experimentally injured, e.g., by actual 

 fracture or by stripping off the periosteum before the organisms are 

 injected, then a much more extensive suppuration occurs at the injured 

 part. 



Erysipelas. — A spreading inflammatory condition of the skin 

 may be produced by a variety of organisms, but the disease 

 in the human subject in its characteristic form is almost 

 invariably due to a streptococcus, as was shown by Fehleisen in 

 1884. He obtained pure cultures of the organism, and gave it 

 the name of streptococcus erysipelatis ; and, further, by inocu- 

 lations on the human subject as a therapeutic measure in 

 malignant disease, he was able to reproduce erysipelas. As 

 stated above, however, one after another of the supposed points of 

 difference between the streptococcus of erysipelas and the strepto- 

 coccus pyogenes of suppuration has broken down. It must 

 be noted, however, that erysipelas passes from patient to patient 

 as erysipelas, and purulent conditions due to streptococci do not 

 appear liable to be followed by erysipelas. On the other hand, 

 the connection between erysipelas and puerperal septicsemia is 

 well established clinically. 



In a case of erysipelas the streptococci are found in large 

 numbers in the lymphatics of the cutis and underlying tissues, 

 just beyond the swollen margin of the inflammatory area. As 

 the inflammation advances they gradually die out, and after a 

 time their extension at the periphery comes to an end. The 

 streptococci may extend to serous and synovial cavities and set 

 up inflammatory or suppurative change, — peritonitis, meningitis, 

 and synovitis may thus be produced. 



Conjunctivitis. — A considerable number of organisms are 

 concerned in the production of conjunctivitis and its associated 

 lesions. Of these a number appear to be specially associated 

 with this region. Thus a small organism, generally known as 

 the Koch-Weeks bacillus, is the most common cause of acute 



