790 Mycetoma, or Madura-foot 



Milk. — The organism grows in milk without causing coagulation. 



Potato. — -Upon potato the growth of the organism is meager and 

 slow, with very little chromogenesis. The color-production is more 

 marked if the potato be acid in reaction. Some of the colonies upon 

 agar-agar and potato have a powdery surface, either from the forma- 

 tion of spores or of aerial hyphae. 



Lesions. — Microscopic study of the diseased tissues in myce- 

 toma is not without interest. The healthy tissue is sharply sepa- 

 rated from the diseased areas, which appear like large degenerated 

 tubercles, except that they are extremely vascular. The mycelial 

 or filamentous mass occupies the center of an area of degeneration, 

 where it can be beautifully demonstrated by the use of appropriate 

 stains, Gram's and Weigert's methods being excellent for the pur- 

 pose. The tissue surrounding the nodes is infiltrated with small 

 round cells. The youngest nodules consist of granulation-tissue, 

 whose development is checked by early coagulation-necrosis. Giant- 

 cells are few. 



Not infrequently small hemorrhages occur from the ulcers and 

 sinuses of the diseased tissues; the hemorrhages can be explained by 

 the abundance of small blood-vessels in the diseased tissue. These 

 may partly explain the occurrence of considerable iron in granular 

 detritus about the fungi. 



The general tendency is for the older lesions to heal with the for- 

 mation of much connective-tissue induration, as new lesions form on 

 the outskirts. 



B. THE MELANOID VARIETY 



Aspergillus Bodtfardi? 



General Characteristics. — A pathogenic hyphomycete composed of branching 

 septate hyphas 3-8^ in diameter. It is non-motile, non-flagellate, non-sporogen- 

 ous, liquefying (?) aerobic or optionally anaerobic, and is pathogenic for man. 



This form of mycetoma depends upon an entirely different micro- 

 organism from that causing the ochroid form of the disease, and 

 properly classed among the hyphomycetes. It was probably first 

 seen by Carter.* Bristowe,t Hogg,t Barsini,§ Kanthack,|| Boyce 

 and Surveyor** and Wrightff have all observed and studied it. 



Wright found it in the diseased tissues, taken from the pads of a 

 toe of a patient who came for treatment in the Massachusetts Gen- 

 eral Hospital. It occurred in the form of black granules that were 

 embedded in the tissue and appeared mulberry-like and less than 

 I mm. in diameter. They were firm, and when enucleated and 



* "On Mycetoma or the Fungus Disease of India," London, 1874. 



t Trans. Path. See, London, 1871. 



j Trans. Path. Soc, Lond., 1872. 



§ Arch, per le scienza mediche, 1888, xii, 309. 



II Jour. Path, and Bact., 1893, i, 140. 

 X* Trans. Royal Soc, London, 1894. 

 ft Jour. Exp. Med., i8g8, in, 421. 



