242 



Dr. G. Thin. 



The vitreous humour used had been prepared in the manner 

 described in a paper on Bacterium foeticlum (" Proc. Roy. Soc.," No. 

 205, 1880), and the hairs were laid on this pure fluid, and placed in 

 the incubator in protected glasses. The only source of contamination 

 was the organisms that were introduced with the hair. Experiment 

 showed that whilst in all cases there was a free development of 

 bacteria, the development of adventitious fungi was frequently 

 avoided. 



The following table gives the results of twelve cultivations made 

 bv this method : — 



Cultivations on the surface of Vitreous Humour in Test-glasses in the 



Jncubator. 



No. of 



Growth of 



No. of days 



E em arks. 



experiment. 



trichophyton. 



in inc abator. 



1 



No. 



6 



Adventitious fungi grew. 



2 



No. 



6 





3 



Yes. 



3 





4 



Yes. 



2 





5 



Yes. 



2 





6 



Yes. 



4 





7 



No. 



8 





8 



Yes. 



8 



Slight growth. 



9 



Yes. 



3 



10 



Yes. 



7 





11 



Yes. 



3 



Slight growth of trichophy- 

 ton : much adveniitious 

 funoi. 



12 



No. 



6 



Growth of aspergillus. 



One experiment was made to ascertain whether trichophyton could 

 be cultivated at ordinary temperatures. 



On the 20th April several ringworm hairs were placed on the 

 surface of vitreous humour in a protected flask, which was put aside 

 and kept at the ordinary temperature of the work-room. On the 

 3rd May the hairs were examined. Trichophyton was found to be 

 growing from their edges, but the growth was not so luxuriant as it 

 was usually found to be after two days' cultivation when the test- 

 glass was kept in the high temperature of the incubator. 



In one recorded experiment the hairs extracted from a ringworm 

 patch did not happen to contain trichophyton. After three days' 

 cultivation in the incubator no fungus of any kind had grown. 



Several other similar experiments, which were not accurately 

 noted, showed that if a hair which did not contain trichophyton was 

 not much exposed before being placed on the vitreous humour, the 



