168 VEGETABLE PARASITES. 



trophiecl sebaceous follicles. It is most probable, according 

 to Bazin, since the favus-matter is constantly found at the 

 lower portion of the epidermal part of the channel of the hair, 

 below the opening of the follicle in the skin (Bazin's " termi- 

 naison de la membrane capsulair^ interne, ") that the parasite 

 originates here, and is sending its branches forth into the interior 

 of the hair, and outwardly underneath the epidermis. The 

 epidermal canal is firmly attached to the hair, preventing the free 

 exit of the fungus, and forming the centre of the cup-like cavity 

 (godet). On growing, the fungus moves more towards the skin 

 between the two layers of the epidermal envelope. 



The fungus shows itself simultaneously in several capsules of 

 the same follicle, when the favi occur in groups (Porrigo scuti- 

 formis). The little cups of the favus press one upon the other, 

 become deformed, and burst the skin which covers them. This 

 is proved by the fact, that the Porrigo scutiformis becomes, after 

 the first epilation and washing with the favus-remedy, a Porrigo 

 disseminata, which after several weeks runs again together from 

 the remaining milk-hairs. On other parts of the body, where 

 the hair is destroyed, and the bulbs not deeply seated in the 

 skin, only the disseminated favus is found. Guddeii has even 

 more accurately determined its seat. He considers the normal 

 epidermis, or the epidermal tissue in general, and the little 

 funnels of the hair in particular, to be the original places of ger- 

 mination of the Achorion, from whence it spreads into crevices 

 and wounds. Its spreading is very much assisted by a delicate, 

 moist skin. The fungus penetrates from the hair-funnels either 

 into the hair itself or into the surrounding epidermis, forcing its 

 filaments inside the sheath between the scaly rings, which they 

 drive away from the shaft of the hair, or, penetrating deeper and 

 undermining the whole, cover it in all directions. They arrive 

 thus sometimes, but rarely, between the longitudinal fibres, and 

 then run parallel to the longitudinal axis of the hair. Wedl 

 gives a similar illustration of it, and this is no doubt the reason 

 why Hebra declares Herpes tonsurans and Favus to be iden- 

 tical. If, however, the immense bulk of the hair occasioned 

 by the spores in Herpes tonsurans is compared herewith, and 

 if, moreover, the observations of so acute an observer as Gudden 

 are repeatedly confirmed, that the spores never penetrate very 

 far and very deep into the tuft of hair, nor very far into the epi- 

 dermis of the skin below the hair, i. e. } into the outer sheath, 



