238 
DR. E. KLEIN ON THE SMALLPOX OE SHEEP. 
vessels of the peripheral part of the pocks with great distinctness into the interfascicular 
spaces and towards the lymphatic vessels of the central part of the pock; at the 
same time the interfascicular spaces of this as well as of the deep stratum in the 
centre of the pock are very well marked by the presence of a homogeneous or slightly 
granular material, which stains blue in hsematoxylin, and with which those spaces are 
more or less filled. This material is in all probability plasma which fills the inter- 
fascicular spaces, and which, being alkaline, becomes stained blue by hsematoxylin. 
The connective-tissue corpuscles show marked changes, their nuclei being in the act 
of division or already divided and the cells themselves swollen and coarsely granular. 
Many of the nuclei of the connective-tissue corpuscles appear to be vacuolated. 
As regards the glands, we may briefly state that the changes are similar to those of 
the epidermis. In the hair-follicles and the sebaceous glands the nuclei of the epithelial 
cells of the most external layer, corresponding to the deepest layer of the rete Malpighii, 
are in a state of very active proliferation, being smaller and much more numerous than 
in the healthy parts. The epithelium of the ducts of the sebaceous glands is very much 
thickened, and the more superficial layers of its epithelium, i. e. those nearer to the 
lumen of the gland, are also composed of cells which are somewhat dropsical, and which 
contain rows of highly refractive granules near the poles of the nucleus. 
The horny transformation of the rete Malpighii also extends to the epithelium of the 
mouths of the ducts of the sebaceous glands and hair-follicles. The epithelium of the 
proper secreting part of the sweat-glands seems to resist longer than that of the sebaceous 
glands and hair-follicles, remaining longer unchanged : pocks, however, which are about 
six or seven days old and more show the external membrana propria of the sweat- 
glands thickened ; the epithelium which lines the lumen is more or less detached from 
the muscular coat, and the nuclei of the epithelial cells are in the act of proliferation ; 
in general the epithelial cells become more and more loosened, as well from the mus- 
cular coat as from each other. 
The nearer the pocks approach the stage of formation of the pustule the more intense 
becomes the infiltration of the corium, both in the peripheral and central part of the 
pock. The subcutaneous tissue does not show an increase of the infiltration in its 
superficial stratum. 
The very intense infiltration of the peripheral part of the pock next to the surrounding 
healthy zone is an additional cause, and perhaps one which weighs materially, why the 
peripheral part of the pock appears very much elevated in respect to the centre. 
A very peculiar change takes place in the lymph-corpuscles which occupy the inter- 
fascicular lymph-spaces of the deep stratum of the corium and of the superficial stratum 
of the subcutaneous tissue, viz. the lymph-corpuscles, or rather their nuclei, break up 
into a number of small particles, deeply stained by heematoxylin ; these particles are 
found of all sizes, from the size of a minute granule up to the size of an intact nucleus 
of a lymph-corpuscle. 
The connective-tissue bundles of the infiltrated corium lose their distinct fibrillar 
