184 
A. ZUNDEL. 
tions of the sub-horny tissues; no radical change of their sub¬ 
stance, and no deposit of heteromorphous molecules in their 
structure. This last mentioned fact was well observed by 
Robin, who in his microscopical remarks constantly observed the 
absence of the characterizing elements of canker. Hertwig and 
Haubner, who have made researches in the same direction, ar¬ 
rived at the same result and have noticed the absence of any can¬ 
cerous cells in canker. This opinion is, however, doubted by 
Glisberg and Fuchs, who look upon canker as an epithelioma, 
though they bring no sufficient evidence to establish it. 
Except vegetal parasitism, of which we will speak hereafter, 
and which makes of canker a true dartre, an herpetic disease, as 
demonstrated by Megnin, there is only in canker a chronic in¬ 
flammatory condition of the sub horny tissues which is manifest¬ 
ed by a perversion in their secretion, and is complicated by a 
morbid hypertrophy of the villous processes by which their sur¬ 
face is normally covered. Robin has seen in the fici, papilloe 
made thicker and more brittle by the plastic infiltration which 
moistens them; he has observed besides, that at the points 
where the secretion is good, it is so active, that instead of drying 
in sheaths, to scale off afterwards in transverse pieces, as nor¬ 
mally occurs in the frog and sole, the epithelial cells grow length¬ 
wise, as those which form the walls of the foot. Hence these 
long, horned, twisted threads (epithelioma ?) which are seen rising 
from the sole of long affected cankerous feet. 
It has sometimes been admitted that fici had deep roots in 
the tissues, and even in the plantar aponeurosis, which is an 
error; injections and macerations having shown that there are 
no essential changes in the anatomical structures of these parts, 
and that what have been considered as the roots of fici were 
only cellular tissue, which has become indurated under chronic 
inflammation (Bouley.) Fici are only fasiculi 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 amongst skin diseases, with and after dartroid af¬ 
fections, and thus gave reason to Huzard senior; Plass also found 
that canker had the greatest analogy with grease, and that in it 
