114. DR. E. KLEIN. 
Histotocicat Notes. By BH. Krein, M.D., ¥.R.S., Lecturer 
on Histology and Embryology in the Medical School of 
St. Bartholomew’s Hospital. 
DissEctine the salivary glands of the guinea-pig I noticed 
various points in their arrangement and structure which I do 
not think have been observed by others, and therefore deserve to 
be described. 
Removing the skin of the facial and cervical regions the 
salivary glands present themselves in the following arrangement : 
1. The parotid occupies the position as in the rabbit, dog, 
cat, and other mammals; it is very flat, its lobules loosely con- 
nected and scattered over a considerable area. Its colour and 
structure is the same as in other mammals. The lower part of 
the parotid, z.¢. in the region of the angle of the inferior 
maxilla, but not specially marked off from the rest of the gland, 
is much thicker, and extends as a compact body, of about 
15—20 mm. in length and 10 mm. in breadth, in a transverse 
direction. 
Fixed to the posterior margin of this oblong thickened 
portion, but surrounded by its own connective-tissue capsule, 
is a small, oval, and somewhat flattened, whitish-looking body. 
Its length is about 8 mm. its breadth 5 mm. and its thickness 
between 2 and 3 mm. Its structure is identical with that of 
the submaxillary of the dog, that is, it is a mucous gland. The 
intralobular ducts are, like the salivary tubes of Pfltiger, lined 
with columnar epithelial cells, whose outer portion is conspicu- 
ously fibrillar. The alveoli are branched and convoluted tubes, 
their relatively small lumen is lined with a single layer of 
columnar mucous cells of the ordinary description. There is, 
however, this distinction between.the gland under considera- 
tion and the submaxillary of the dog, that there are no cres- 
cents in the alveoli of the former. I have carefully searched 
for them but failed to find them. 
In a gland in which the ducts appear filled with a granular 
secretion the mucous cells of the alveoli show more or less 
distinctly two zones, an outer and an inner zone, the latter more 
transparent than the former. In a former paper (this Journal, 
April, 1879) I have called attention to a similar differentia- 
tion in the mucous cells lining the alveoli of the submaxillary 
of the dog. 
The efferent duct lies on the side next the parotid, whose 
large ducts it joins. 
Claude Bernard saw occasionally small mucous glands con- 
