CULTIVATION OF ACTINOMYCES 333 



extraperitoneal tissue, the retrocaecal connective tissue and that 

 around the rectum being not uncommonly seats of suppuration 

 produced in this way. A peculiar affection of the intestine has 

 been described, in which slightly raised plaques are found both 

 in the large and small intestines, these plaques being composed 

 almost exclusively of masses of the actinomyces along with 

 epithelial cells. This, however, is a rare condition. The path 

 of entrance may also be by the respiratory passages, the primary 

 lesion being pulmonary or peribronchial ; extensive suppuration 

 in the lungs may result. Infection may occur by the skin 

 surface, and lastly, by the female genital tract, as in a case 

 recorded by Grainger Stewart and Muir, in which both ovaries 

 and both Fallopian tubes were affected. 



When the parasite has invaded the tissues by any of these 

 channels, secondary or " metastatic " abscesses may occur in 

 internal organs. The liver is the organ most frequently affected, 

 though abscesses may occur in the lungs, brain (where a primary 

 meningitis may also occur), kidneys, etc. In such cases the 

 spread takes place by the blood stream, and it is possible that 

 leucocytes may be the carriers of the infection, as it is not 

 uncommon to find leucocytes in the neighbourhood of a colony 

 containing small portions of the filaments in their interior. 



In the ox, on the other hand, the disease usually remains 

 quite local, or spreads by continuity. It may produce tumour- 

 like masses in the region of the jaw or neck, or it may specially 

 affect the palate or tongue, in the latter producing enlargement 

 and induration, with nodular thickening on the surface the 

 condition known as "woody tongue." 



Source of the Parasite. There is a certain amount of 

 evidence to show that outside the body the parasite grows on 

 grain, especially on barley. Both in the ox and in the pig the 

 parasite has been found growing around fragments of grain, 

 embedded in the tissues. There are besides, in the case of the 

 human subject, a certain number of cases in which there was a 

 history of penetration of a mucous surface by a portion of grain, 

 and in a considerable proportion of cases the patient has been 

 exposed to infection from this source. Doubt has, however, been 

 recently thrown on this view (p. 335). 



Cultivation (for methods of isolation see later). The descrip- 

 tions of the cultures obtained by various investigators differ in 

 essential particulars, and there is no doubt that the organisms 

 described are different. The following is the account of the 

 organism as cultivated by Bostrom : 



On agar or glycerin agar at 37 C., growth is generally 



