TRICHOPHYTON TONSURANS. 141 



Vegetabile unice ex sporis formatum. Spori rotundi ^tut ovales, 

 pellucidi, sine colore et in superficie laves ; diameter 0-003 6 

 8 mm. 



Habitat : In interna parte radicis capilkrum, ubi spori firmant 

 acervum rotundum. Ex sporis exeunt filamenta articulata, 

 qua sunt spori, in filamentis moniliformibus positi, et, dum sese 

 evolvunt, substantiam capilli penetrantes } eumque per totam longi- 

 tudinem peragrantes. 



Species Trichophyton tonsurans. 



Synon. : Trichomyces tonsurans ; = Epiphytes = Mycoderma = 

 Trichomaphytes plica polonies ; Champignon des cheveux dans 

 THerpes tonsurans; = Champ, voisin de celui de la teigne, by 

 Lebert ; = Champ, de la teigne fondante, du Porrigo scutulata 

 ou Herpes tonsurans ; = Achorion Lebertii ; = Cryptogame de la 

 teigne tondante ou de la Rhizo-phyto-alopecie. Porrigo circin- 

 nata and Porrigo tonsoria are synonyms for the disease accom- 

 panying this fungus. 



Habitat : Unice in interna parte radicis capillorum humanorum, 

 sed non in eorum superficie. Post capillorum rupturam invenitur 

 in crustis epidermidis et sebaceis capitis pileati. 



The filaments placed in rows in which the spores originate 

 have undulated edges, and show in their interior, at small 

 intervals, the round spores, rarely so long as to imitate the 

 filaments, and peculiar to the Cryptogamia. These spores are 

 round, transparent, half as large as blood-corpuscles, 0'003 7 

 O'OOIO mm. long and 0-003 4 broad. Many have in their 

 interior a distinct spot or vaguely defined nucleus ; many, when 

 they are long in shape, appear to have a constriction in the 

 middle. There are no partition walls, although it appears as if 

 they existed, when the spores are very close together. 



The medium in which this fungus is found is not, as it might 

 appear, the space between the cells of the epidermis, where they 

 are never met with, but in the substance of the root of the hair 

 itself, though it remains yet very doubtful whether this fungus 

 thrives only in diseased or also in healthy hair, after its spores 

 have once penetrated the substance of the hair. The spores 

 form at first a round heap, which spreads more or less upwards 

 in a straight line with the longitudinal axis of the hair-mass, 

 which is thus enlarged till it brings on a state of disease known 

 under the name of tinea or herpes tonsurans. The fungus goes 

 on growing with the hair, and when it has grown 2 or 3 mm. 



