DISTRIBUTION OF THE LESIONS. 



293 



the wall of the bowel, and may be found deeply between the 

 coats, surrounded by purulent material. Ulceration, and some- 

 times a considerable amount of necrosis, may follow. Thence it 

 may spread to the peritoneum or to the 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 placques are found both in the large 

 and small intestines, these placques being composed almost ex- 

 clusively of masses of the actinomyces along with epithelial 

 cells. This, however, is a very 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 in- 

 ternal 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 

 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 



