Morphology 



813 



ball of the great toe and the pads of the fingers and toes 

 are the points most frequently invaded. The lesions pro- 

 gress very slowly, and in the course of a few months form 

 distinct inflammatory nodes. After a year or two the 

 nodes begin to soften, break down, discharge necrotic and 

 purulent material, occasioning the formation of ulcers and 

 sinuses. The matter discharged from the lesions at this 

 stage of the disease is a thin seropus, and contains occasional 

 fine round pink or black bodies, similar to actinomyces 

 " grains," described, when pink, as resembling fish-roe; 

 when black, as resembling gunpowder. It is upon the de- 

 tection of these particles that the diagnosis rests. Accord- 

 ing to the color of the bodies found, cases are divided into the 

 pale or ochroid, and melanoid varieties. 



The progress of the disease causes an enormous enlarge- 

 ment of the affected part. 

 The malady is usually pain- 

 less. 



The micro-organismal na- 

 ture of the disease was early f|r 

 suspected. In spite of the 

 confusion caused by some 

 who confounded the disease 

 with "guinea- worm," Carter 

 held that it was due to some 

 indigenous fungus as early 

 as 1874. Boyce and Sur- 

 veyor found that the black 

 particles of the melanoid 

 variety consisted of a large 

 branching septate fungus. 



Pale Variety. -- Kan- 

 thack was the first to prove 

 the identity of the fungus 

 with the well-known actino- 

 myces, but there seems to be 

 considerable doubt about the 

 identity of the species: 



Morphology. Under the 

 microscope the organism is 

 found by Vincent* to be 



branched and belong to the higher bacteria. It consists of 

 * "Ann. de 1'Inst. Pasteur," 94, 3. 



Fig. 270. Streptothrix mad- 

 urae in a section of diseased tis- 

 sue (Vincent). 



