236 



Dr. G. Thin. 



avoid confusing accidental growths of common fnngi with the spores 

 and mycelium of the parasite. The size of the spores and mycelium 

 is not to be relied on for this purpose, but their arrangement in an 

 affected hair offers facilities for ascertaining whether in any given case 

 trichophyton has developed. 



When a hair is extensively affected with ringworm fungus, the root 

 for a considerable extent is loaded with spores in all its thickness, and 

 along its free borders the spores on the extreme edge can be seen 

 under the microscope with perfect distinctness. It was thus evident 

 to me that if there were observed at an early stage of the culti- 

 vation a growth of those spores in the sides of the hairs which from 

 their position could be recognised as ringworm spores, the fallacy of 

 deception by admixture of adventitious fungi would so far be avoided. 



At an early stage of my investigations, Mr. Banhani, of the Brown 

 Institution, showed me a preparation in which ringworm spores had in 

 considerable numbers pushed out a tubular projection, by which their 

 length had become at least double their breadth, and which was 

 evidently the beginning of growth. This growth had taken place in a 

 prepared cell in a drop of aqueous humour, but Mr. Banham informed 

 me that he had not succeeded in getting the cultivation to go farther. 



The first attempts I made at cultivation were with ringworm hairs, 

 which had been kept in my house for varying periods, having been 

 put aside for the purpose of the investigation ; but, after a series of 

 negative results, I confined myself entirely to hairs freshly extracted 

 from the heads of children affected with ringworm. These were 

 usually put in the different solutions with which I experimented 

 within periods varying from a quarter of an hour to two hours. When 

 these ringworm hairs are placed in contact with fluids at a high tem- 

 perature (92° to 98° R), the spores soon show an outer surface or 

 capsule, containing a spherical mass within it. This seems to be to 

 a great extent independent of the nature of the fluid, and it is very apt 

 to be mistaken for the first beginning of growth. When growth does 

 not take place the appearance remains stationary- A variety of solu- 

 tions were tried without result. These were used at first in cells, the 

 hair being laid on the inner surface of the cover-glass of the cell and a 

 drop of the solution placed over it. The hair was sometimes covered 

 with the drop and sometimes only moistened ; in the latter case a ring 

 of damp blotting-paper was placed in the bottom of the cell, to prevent 

 evaporation. The cells were then placed in an incubator. The 

 temperature within the incubator varied during the course of the 

 experiments between 92° and 98° F., but was mostly from about 96° 

 to 98°. 



As these negative results afford evidence that Trichophyton ton- 

 surans and the fungi usually present in the atmosphere are essentially 

 different, they are worthy of being recorded. 



