DE. E. KLEIN ON THE SMALLPOX OE SHEEP. 
229 
directions, and cross and join each other very closely. This stratum contains, in that 
layer which is nearest to the surface, the sebaceous glands, a little deeper the roots of 
the hair -follicles, and in the deepest layer the sweat-glands. 
( d ) The subcutaneous tissue between the corium and the panniculus adiposus may 
also be divided into two strata, a superficial and a deep one. This superficial stratum 
is very markedly different from the deep stratum of the corium ; for it consists of large 
broad bundles of connective tissue, which run in two, or generally in three, directions ; 
they are by no means so close as in the latter, and the interfascicular spaces are there- 
fore more distinct and much larger. The amount of elastic tissue is not great. 
This stratum contains the minor trunks of the blood-vessels and the lymphatics, which 
run to or from the corium ; they are not very numerous. 
The deep stratum of the subcutaneous tissue is similar in its structure to the former ; 
it is still looser, and contains the main trunks of the blood-vessels and lymphatic vessels, 
and also a greater or smaller amount of fat-tissue, either in the act of development or 
already fully developed. 
(e) The sebaceous glands are characteristic for being enormously large in respect to 
the hair-follicles into which they lead ; they are short, slightly branched tubes, swollen 
at their end, and lead into a large duct, which is identical with the mouth of the hair 
follicle. The sebaceous glands of the groin and the axilla are the largest. The hair- 
follicles are possessed of arrectores pili, which, relatively to the size of the hair-follicles, 
are of very great strength. When, after an oblique course around the sebaceous gland, 
they enter the superficial stratum of the corium, they split in two, three, or more minor 
bundles, which can always be traced very close to the papillary layer, into which they do 
not, however, enter, but generally bend before that into a horizontal direction. 
Each sweat-gland consists in its secreting part of a tube, which is generally convoluted 
in a direction parallel to the surface. The tube consists of an apparently homogeneous 
thick membrane, on the inner surface of which lies one or even two continuous layers of 
longitudinal unstriped muscles. Close to these, without the intervention of a membrane, 
is attached a single layer of nucleated columnar epithelial cells, which line the lumen 
of the gland. 
The duct of each gland becomes narrower the more it approaches the surface, and 
pursues always an almost vertical course ; it leads generally into an epithelial prolon- 
gation of the mouth of the hair-follicle, or, as one might say with equal truth, into the 
mouth of the duct of a sebaceous gland. The duct of the sweat-gland does not possess 
a muscular coat, at least not in some distance from the proper gland, and is lined by 
polyhedral epithelial cells, which become the more laminated (stratified) the nearer to 
its mouth. The lumen of the sweat-duct is much narrower than that of the proper 
gland, and is reduced at its mouth to its smallest diameter *. 
* The sebaceous glands of the lips of the mouth are different from the sebaceous glands above described, the 
former (glands of the lips) being very much longer; they consist generally of a number of narrow ducts leading 
into a common hair-follicle. They are of a relatively great length, and terminate in a number of wavy, pear- 
shaped, somewhat branched sacs. 
MDCCCLXXV. 2 I 
