XI, B, 6 Wade: Cultivation of a Pathogenic Fungus 269 



These nodules upon incision usually appear much less than noi-mally 

 sensitive. The tissue is very friable and tears readily. Incised wounds 

 heal promptly and cleanly unless secondarily infected. Such an infection 

 is apparently not uncommon and results in more or less persistent ulcers, 

 which are shallow, do not increase in size or do so slowly, exude constantly, 

 and heal reluctantly. Excess scar formation has followed as a rule. 



During a period of two months' observation the changes that took place 

 were of minor importance. As a whole, more and more of the skin surface 

 was being encroached upon. The patient's general condition was fairly 

 good, though he was slightly anaemic and below normal in strength. 



STUDY OF ORGANISM 



At various times smears and cultures were made, and on 

 three occasions tissue was excised for study. After several un- 

 successful attempts to cultivate it, the fungus was recovered in 

 its free-growing form. In the earlier cultures there were isolated 

 from certain acute, unbroken lesions a nonhaemolytic Strepto- 

 coccus pyogenes and a delicate diphtheroid. In view of the find- 

 ings of Rosenau(9) in erj'thema nodosum, these were studied 

 somewhat fully, but they proved not to be significant except as 

 secondary invaders. 



In the earlier cultures the fungus was not recognized, though 

 certain of its forms were later found to have been present in 

 some of the preparations from these cultures. 



In describing the various appearances of the organism, it 

 seems advantageous to apply tentatively selected names to forms 

 which, it appears, are not covered by any accepted terminology. 

 These are a, the "basic parasitic form," a simple, usually round, 

 densely staining, more or less nucleuslike body, from which other 

 forms develop ; h, the "entire-cell form," which is evolved by the 

 development of a distinct protoplasm about the basic form ; c, the 

 "spore-granules," produced under conditions of semiparasitism, 

 which are given this qualified designation because they are very 

 different from the usual spores of fungi and, to a less extent, 

 from common bacterial spores ; and d, the "gelatinous body," 

 another semiparasitic form, which is a peculiar cultural develop- 

 ment of the basic form. 



HISTOPATHOLOGY 



The tissue forms of the parasites were first found in smears 

 and sections of the soft, granular tissue of a fairly recent, un- 

 complicated lesion. A small piece was removed and placed in 

 Zenker's fluid; cultures were made from the cut surface. In 

 these cultures there later appeared the first recognized multipli- 

 cation of the fungus. 



The tissue studied was from the nodule proper and is com- 



