238 DR. KLEIN. 
so dense that the whole presents the aspect of a felt-like 
mass. 
5. The process thus commenced makes rapid progress. 
After one or two days the greater number of the lymphatics 
of the affected part of the corium become filled with the 
vegetation above described ; and on careful examination of 
the masses it is seen that they present the characters of a 
mycelium, from which necklace-like terminal filaments 
spring, each of which breaks off at its free end into conidia. 
In most of the filaments a jointed structure can be made 
out, and in the larger ones the contents can be distinguished 
from the enclosing membrane by their yellowish-green 
colour. 
The necklace-like filaments are well seen in fig. 7. They 
are contained in a lymphatic vessel of the corium similar to 
those represented in figs. 4, 5, and 6, 
Fie. 8. 
Separated conidia, in a state of germination, are shown in 
fig. 8, as seen under a much higher power. 
6. At the same time that these appearances present them- 
selves in the corium, those changes are beginning in the now 
much thickened rete Malpighii, which are preparatory to the 
formation of the vesicular cavities already mentioned. By a 
process which I propose to designate horny transformation, 
having its seat in the epithelial cells of the middle layer of 
the rete Malpighii, a horny expansion or stratum appears, 
lying in a plane parallel to the surface, by which the rete 
Malpighii is divided into two parts, ‘of which one is more 
superficial, the other deeper than the horny layer. Simul- 
taneously with the formation of the horny layer the cells of 
the rete nearest the surface of the corium undergo very active 
