CONJUNCTIVITIS 191 



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 in- 

 variably 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 that of 

 suppuration has broken down, and it is now generally held that 

 erysipelas is produced by the streptococcus pyogenes of a certain 

 degree of virulence. It must be noted, however, that erysipelas 

 passes from patient to patient as erysipelas, and purulent con- 

 ditions due to streptococci do not appear liable to be followed 

 by erysipelas. On the other hand, the connection between 

 erysipelas and puerperal septicaemia 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 

 contagious conjunctivitis, especially prevalent in Egypt, but 

 also common in this country. This organism is very minute, 

 being little more than 1 /* in length, and morphologically 

 resembles the influenza bacillus ; its conditions of growth are 

 even more restricted, as it rarely grows on blood agar, the best 

 medium being serum agar. On this medium it produces minute 

 transparent colonies like drops of dew. The obtaining of pure 

 cultures is a matter of considerable difficulty, and it is nearly 

 always accompanied by the xerosis bacillus. It can readily be 



