244 



Dr. G. Thin. 



experiments made, I undertook cultivations with hairs extracted from 

 patches which were under active treatment for the cure of the 

 disease. "With one exception, and in that one the growth was open to 

 doubt, all these cultivations failed. Nineteen such cultivations were 

 attempted, in two the hairs being on the vitreous humour in the incu- 

 bator for two days, in eight for three days, in six for four days, and in 

 three for five days. The treatment had consisted in rubbing into the 

 scalp, on the affected places, sulphur ointment and mercurial ointments 

 of various kinds and strengths. 



The failure to cultivate trichophyton in these cases did not coin- 

 cide in point of time with the cure of the disease, for in many of them 

 the malady followed its somewhat tedious course for a considerable time 

 after the dates of the experiments. 



The fact that 1 had been unable to produce growth of tricho- 

 phyton in cells, so long as the spores were completely immersed in 

 vitreous humour, led me to make the following experiments. Ring- 

 worm hairs were extracted from a patch of untreated ringworm. Some 

 of them were inserted into a small glass tube, which was placed at the 

 bottom of the test-glass, and others were floated on the surface of the 

 fluid in the usual way. After two days the hairs were examined. 

 There was an abundant growth of mycelium around the roots of those 

 hairs which were on the surface. The mycelium was of the size of 

 that of ringworm, and in some of it black pigment had been depo- 

 sited. No spores had formed. I satisfied myself at the time that it 

 had developed from the ringworm spores. On macerating the hairs 

 the mycelial growth of trichophyton inside the hair-shafts was also 

 found pigmented. 



In the hairs deposited in the tube at the bottom of the test-glass no 

 growth had taken place, although on maceration they were found to 

 contain mycelium and spores of trichophyton, both containing black 

 pigment.* 



In another instance, in which the experiment was conducted in pre- 

 cisely the same conditions, an examination was made after the test- 

 glass had been six days in the incubator. There was free growth of 

 trichophyton in the hairs which had been floating on the surface 

 of the fluid, whilst there was no growth in the hairs which were in the 

 tube at the bottom of the glass. 



In these two experiments all the hairs, both those on the surface and 

 those at the bottom, contained trichophyton, and in each experiment 

 both the surface and the sunk hairs were taken at the same time from 

 the same patient, every condition being alike, except that in the one 



# This patient is not the only one in whose diseased hairs the ringworm fungus 

 was pigmented. I have found the same peculiarity in other cases, and in the 

 affected hairs from a patch of this disease, in a black horse, I found pigmented my- 

 celium and spores very common. 



