MYCETOMA, OR MADURA-FOOT. 365 



attaining the size of a small pea. They are generally 

 umbilicated like a variola pustule, and present a curious 

 appearance when the central part is pale and the periphery 

 red. As the colony ages the red color is lost and it be- 

 comes dull white. The colonies are very adherent to the 

 surface of the medium, and are said to be of cartilaginous 

 consistence. The organism also grows in milk without 

 coagulation. 



Upon potato the development is meagre, slow, and 

 with very little tendency to chromogenesis. The color- 

 production is more marked if the potato be acid in reac- 

 tion. Some of the colonies upon agar-agar and potato 

 have a powdery surface, no doubt from the occurrence of 

 spores. It is, of course, an aerobic organism. 



Under the microscope the organism is found by Vin- 

 cent to be a streptothrix — a true branched fungus con- 

 sisting of long bacillary branching threads in a tangled 

 mass. In many of the threads spores could be made out. 

 Vincent was unable to communicate the disease to animals 

 by inoculation. 



Microscopic study of the diseased tissues in cases of 

 mycetoma is not without interest. The healthy tissue 

 is said to be sharply separated from the diseased masses. 

 The latter appear as large degenerated tubercles, except 

 that they are extremely vascular. The mycelial or 

 filamentous fungous mass occupies the centre of the 

 degeneration, where its long filaments can be beautifully 

 demonstrated by the use of appropriate stains, Gram's 

 method being excellent for the purpose. The tissue sur- 

 rounding the disease-nodes is infiltrated with small round 

 cells. The youngest nodules are seen to consist of granu- 

 lation-tissue, which in its organization is checked by the 

 coagulation-necrosis which is sure to overtake it. Giant- 

 cells are few. 



Not infrequently small hemorrhages occur from the 

 ulcers and sinuses of the diseased tissues ; the hemor- 

 rhages can be explained from the abundance of small 

 blood-vessels in the diseased tissue. 



