xiii, b, 4 Wade: Studies on Cryptoplasmic Infection 183 



The possibility that it is a laboratory contaminant of the 

 cultures cannot, of course, be denied. However, in view of its 

 characteristics, and in the light of experience with the conditions 

 in this laboratory, this seems to me improbable. The cultures 

 were paraffin-sealed, and at no time showed any evidence what- 

 ever of ordinary contamination. They at first contained only the 

 curious cell-fragment forms among the bacteria, a staphylococcus 

 in one case and a proteuslike bacillus in the other. After dif- 

 ferent periods of time the Cryptococcus was also found. 



The fungus itself was unlike any of the many strains of yeast- 

 like organisms of which I have found descriptions or have my- 

 self met with. I have never seen any laboratory contaminant 

 that resembled it in the slightest, and it is totally unlike the 

 fungi of that class that I have from time to time cultivated from 

 sputum, urine, fasces, fruit, etc., here and elsewhere. Its cha- 

 racteristic features of nonproduction of visible colonies, of an 

 unusual and evidently very slow process of multiplication, of 

 noncultivability in fresh subplants away from the remnant of 

 the tissue material originally planted, though put on media part- 

 icularly adapted to the cultivation of fungi, are not suggestive 

 of a saprophyte but, on the contrary, bespeak a highly parasitic 

 organism. 



The alternative that the observed fungus is essential to the 

 lesion seems, therefore, quite possible. The appearance of the 

 lesion itself and its course and reaction to potassium iodide 

 are indicative of mycotic infection. Though no fungus element 

 can be demonstrated in preparations from it, the same is true 

 of other microorganisms. The fungus that was found appeared 

 only in cultures of material from two clinically active cases, on 

 a medium (nutrient prune agar) that is especially favorable 

 to the growth of fungi. The characteristics of the two strains 

 seem to be identical and are essentially those of a highly paras- 

 itic organism, as might be expected of the causal agent of such 

 lesions. Therefore the weight of evidence, positive and negative, 

 justifies the serious contemplation, if not the assumption, of the 

 conclusion that the described fungus element represented the 

 infecting organism. 



From the mycologist's point of view the Cryptococcus is, un- 

 doubtedly, to be regarded as a degraded form of a higher fungus. 

 From the viewpoint of the hypothesis outlined above, however, 

 assuming that it is the causal organism, it is apparent that it may 



