478 
DR. E; KLEIN. 
external opening, where the epithelium of the surface is 
stratified pavement epithelium, with a superficial stratum 
like the stratum corneum of the epidermis, also the mouth 
of the duct of the mucous gland receives a continuation of 
this latter stratum. Like the epidermis it stains dark 
in osmic acid. 
The intralobular ducts of the serous glands are iden- 
tical with the salivary tubes of Pfliiger, viz. they are 
lined with a layer of columnar cells, the outer portion of 
which is distinctly longitudinally striated. The intralobular 
ducts ultimately branch into several shorter or longer tubes, 
which are very narrow and lined with a layer of flattened 
cells, and they are therefore identical with the intermediate 
portions of the ducts in the salivary glands and the 
pancreas, 
The epithelial cells lining the alveoli are columnar, and 
present themselves in two different aspects according to the 
state of secretion. In one aspect, viz. during secretion, they 
are more transparent, thicker, and appear therefore less 
columnar. Their nucleus is spherical or only slightly flat- 
tened, and pressed against the membrana propria. In the 
other state they are less transparent, thinner, more columnar, 
and their nucleus is spherical, and not quite so close to the 
membrana propria; but in both conditions the cell sub- 
stance is a reticulum, more distinctly so, on account of the 
greater size of its meshes, in the former than in the latter. 
There exists, consequently, also in this respect a complete 
analogy between these and other serous glands. 
In those parts where the mucosa is of great thickness, 
covered with ciliated columnar epithelium, and containing 
s mailer or larger amount of diffuse adenoid tissue, these glands 
form also larger groups, situated in the deep submucous 
section. 
In preparations that had been prepared, when per- 
fectly fresh, with a mixture of chromic acid and osmic acid, 
according to the method of Flesch (‘ Arch. f. mikr. Anat.,j 
Bd. xvi, p. 300), the alveoli of the serous glands, especially 
thcs 3 nearest to the surface, appear much larger, their cells 
being "distended by the presence of smaller or larger . fat- 
globules, isolated or in groups ; consequently there exists, in 
this respect, a certain resemblance of these glands and the 
sebaceous and Meibomian glands. From this it appears, theii, 
probable that tlie secretion of them is not precisely the same 
as in the other serous glands, ^.< 7 . those at the root of the 
tongue or the salivary glands. 
In the interlobular connective tissue isolated lymph-cor- 
