292 ACTINOMYCOSIS AND ALLIED DISEASES 



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 also 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, 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 considerable 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 em- 

 bedded 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. The position of the 

 lesions in cattle is also in favour of such a view. 



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

 scriptions 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 



