248 



Dr. G. Thin. 



Eichhorst* states that in nine cases he found spores on the diseased 

 hairs once, between the shaft and root sheaths. There was no myce- 

 lium, and the spores were about the size of those of the Microsporon 

 furfur. The descriptions given by Gruby, Malassez, and Eichhorst of 

 his solitary case differ from each other; Gruby describing a fungus 

 with mycelium which ensheathes the hair shaft, Malassez single spores 

 of various sizes scattered over the epidermis, and Eichhorst large 

 spores between the hair shaft and root sheaths. 



A hypothesis of another kind has been put forward by Buchner.f 

 Considering that the disappearance of the hair in ever-widening 

 circles which bear no relation to the distribution of blood-vessels or 

 nerves, without any evident cause, is best explained by the theory of 

 parasitism, but yet acknowledging the failure of the attempts that 

 have been made to discover the parasite, this observer asks whether 

 the parasite may not be a bacterium, which on account of its smallness 

 and position in the hair cannot be brought under observation. In 

 support of this hypothesis he instances an experiment which he made. 

 In a case of the disease he extracted hairs from the affected patch 

 with heated forceps (so as to exclude contamination to the greatest 

 possible extent), and placed them in a cultivating fluid. He reasoned 

 that if there are bacteria in the hairs they will be in greater number 

 than the bacteria introduced accidentally with the hairs, and that in 

 the first hours of cultivation they would greatly outnumber these 

 latter. Accordingly, he found in eight successive cultivations a 

 bacterium which he describes as a small refractive sharply contoured 

 particle (TZorncheii), scarcely 0"001 millim. in diameter, with two very 

 fine and short thread-like processes projecting from opposite poles. 

 He remarks that this may not necessarily be the form which the 

 presumed bacterium has in the hair, as the effect of cultivation is 

 sometimes to alter the forms of bacteria. 



The observations which are recorded in the following paper were 

 preceded by desultory studies of hairs extracted from patients suffer- 

 ing from this disease during the five years preceding 1880, of which 

 no notes were taken, my attention having been directed to the subject 

 after the appearance of Malassez 's paper in 1874. 



In none of the hairs, however, which I examined did I discover a 

 fungus. The hairs which I did not have time to examine were put 

 away for future study, carefully folded in paper. 



In examining one of the hairs which had been kept for some time, 

 I observed flakes of a filmy substance fall away from the hair, and 

 imbedded in this substance there were what seemed to me to be great 

 numbers of micrococci. 



From that time when examining hairs from the margin of patches 



* " Virckow's Arcliiv," vol. lxxriii. 

 f " Vircliow's Archiv," yol. lxxiv. 



