cells of which have a normal arrangement, also occur in the deeper 
lying tissue. Structures resembling ‘cell-nests’ have been 
frequently observed both in the epithelial columns and in the 
deeper epithelial collections just mentioned. The ‘prickle-cell’ 
nature of the epithelial down-growths is, as a rule, very clearly 
seen, the intervals between the cells being rather greater than usual 
by reason of inter-cellular oedema. The stratum granulosum and 
the keratinous layer are usually considerably increased in 
thickness. 1 hese features of the epithelium are simply those which 
might be expected to result from any chronic lesion. The 
cell-nests, for instance, have no greater significance than they 
possess in other chronic lesions such as simple warts, scrofuloderma, 
etc. 
I he dermis itsell is the seat of an exceedingly dense and 
uniform cellular infiltration which is continuous beneath the entire 
extent of the lesion. I his infiltration is composed of cells of 
various kinds. The superficial strata of the dermis in the central 
parts of the lesion frequently contain considerable numbers of 
polymorphonuclear leucocytes, as well as free nuclei and other 
cellular detritus, the result of inroads by pyogenic bacteria. More 
ceeply, however, the cellular infiltration is composed almost 
exc usively of mononuclear elements of various kinds. A certain 
p portion of these arc indistinguishable from lymphocytes. In 
st of this cellular zone, small ill-defined areas are observed 
composed of mononuclear cells of much larger size than the 
^ C aSS ' areas » seen under a low power, appear rather 
Cr tlC clcnse small mononuclear infiltration surrounding 
em. The parasites are found in the largest numbers in the 
ex-rh ,0r 1 the cel,s composing such areas, though by no means 
excl uslvely confined to Thc , nfiitrated arcas just descnbed 
canilln \ XtlSCU,ai ’ considerable numbers of small vessels of 
capillary character being present. 
encountered sweat "glands, which are often of course 
but have not ] ^ \ ° S ° me extent in tJ ie surrounding infiltration, 
change ° JSC1VCcl to Sllffer any degenerative or destructive 
areolaT^e'p^'to^t litT gradUa ' Iy meTSeS int ° the n ° rmal 
