DR. CHAMBERS, ON MUCUS AND PUS, 295 
details, and we therefore give a brief abstract of the lectures 
taken from the report of our contemporary, the Lancet. “A 
physiological fellow of our college,” says Dr. Chambers, 
“‘was in the habit of regarding his patients as so many 
‘mucous membranes.’”” The term was no exaggeration, for 
to the medical man the mucous membrane is all-important. 
Most of the drugs administered to his patients act on it, 
and all are introduced through it. The business of mucous 
membrane is to offer a passage for oxygen, water, fat, albu- 
men, and other nutrimentary substances, and to defend the 
less easily renewed tissues beneath it, from the deleterious 
action of external agents. These functions are performed best | 
when it is bedewed with a moderate watery exhalation, and 
not with mucus. It must not be supposed that the secretion 
of mucus is the special function of a mucous membrane ; 
in fact, the membrane is most active when there is least 
mucus. The secretion which usually moistens its surface, 
possesses nothing of that stringy adherent character by 
which we recognise mucus. It is transparent and watery, 
and contains the epithelial scales shed from the surface. 
Shed epithelia are found also in mucus, but not as a peculiar 
characteristic. Its most obvious characteristic is the pre- 
sence of transparent viscid bodies of an oval form, and with 
one or more nuclei in their interior; the fluid in which 
these are placed seems to be that whence the peculiar con- 
sistence and adhesiveness of the mucus is derived. This seems 
to be the case, since oval globules similar to those of mucus 
constitute the bulk also of pus, which has entirely distinct 
attributes and properties. Professor Henle’s view with 
regard to these globules seems very plausible. He considers 
them as young epithelia, prematurely moulted from the 
body. The condition which produces them is an arrest of 
development. The peculiar structure of epidermal tissue is 
well known, consisting of cells flattened externally by pressure, 
and rounder, looser, and more globular as they approach the 
inner surface. This is the structure of both the scarf-skin 
and mucous membrane; the former covering the whole 
external superficies of the body, the latter acting as a pro- 
tection for the surfaces of the various internal viscera and 
canals. - The “ mucous globules,’ of which mention has been 
made, appear to be the young epithelial cells, and may be 
seen by removing the external layer of scales more advanced 
in development. They are exactly identical with the inner 
strata of the epidermis, the rete mucosum of Malpighi. Dr. 
Chambers gives a very minute account of the development of 
these epithelial cells. He says: 
