DISEASES. 599 



what have been considered as the roots of fici were only cellular 

 tissues, which has become indurated under chronic inflammation 

 (Bouley). Fici are only fasciculi of villosities whose vascular net- 

 work is no longer retained by the thick horny box which encloses 

 them and which is infiltrated with plastic material. 



Bouley has already admitted that canker could not be better 

 classified than among skin diseases, with and after dartroid affec- 

 tions, and thus gave reason to Huzard senior ; Plass also found 

 that canker had the greatest analogy with grease, and that in it 

 the nutrition of the horn underwent the same alteration with nu- 

 trition of hairs in the second affection. 



Megnia, in 1864, observed, in operating upon fresh pieces 

 taken from the Uving animal, and from one which had not received 

 any treatment, that in canker there is constantly a cryptogam, as 

 in favus, and that canker is a parasitic affection. 



Examining the caseous product of the abnormal secretion which 

 characterizes canker, Megnin found in it a large quantity of very 

 animated vibrios, swimming in a liquid having in suspension nu- 

 merous epidermic cells more or less advanced in dissolution ; he 

 found besides rounded corpuscles, which he recognized as the 

 spores of the cryptogam, and from which the vibrios escaped at 

 the maturity of the granulations there contained. In examining 

 the fici, he has recognized them to be an aggregate of hypertrophied 

 vUlosites, at the base of which were found in the mass obtained 

 by a slight scraping epidermic cells or parts of cells enclosed in a 

 net-work of inter-crossed, ramified threads, appearing to rise from 

 certain centers marked by an agglomeration of spores, forming in 

 their whole a yellow spot. In the water of the microscopic prep- 

 arations, one finds also several of these isolated threads, epithelial 

 cells, globules of lymph, of blood and finally spores ; very rarely 

 vibrios ; of tener micrococci. These threads are nothing more than 

 the parasites, the mycelium product of the vegetation of the 

 spores ; those contained in the serosity, swell, break up, and the 

 granulations which escape from them become for some time the 

 vibrios, or as we prefer to call them, pseudo-vibrios ; as soon as 

 the brownian motion, which for some time animates the granula- 

 tions, ceases, the cells which have proceeded from them (themicro- 

 cooci) gather together in chains and form the characteristic threads 

 of the mycelium. 



This parasite of canker has been named by Megnin the kera- 



