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OF THE ABSORBENTS.
Do the absorbents communicate with the secreting canals of
glands?—If any open communication between the lymphatics and
secreting canals really exists, which Panizza denies,—and certainly
with justice,—it can only be by means of the trunks of the secreting
canals; for the smaller lymphatics which form the ultimate network,
are many times larger than the blind extremities of the secreting
canals of the conglomerate glands. The connection of ly mphatics
and arteries, of which Magendie speaks so summarily, is not better
proved.
The connection of the lymphatics ivith the small veins, however,
has been again rendered a subject of controversy, in consequence of
Fohmann’s observations.
Fohmann, Lauth, and Panizza, have discovered communications,
visible to the naked eye, between the lymphatics and the veins of
the thigh and pelvis in birds. 1 have also discovered a connection
between the lymphatics of the thigh and the ischiadic vein in the
frog. But this communication of the larger trunks is very different
from a communication of the smaller lymphatic vessels with minute
veins, which Fohmann asserts to exist in birds, reptiles, and fishes,
and of which he has given representations. He admits, however,
that in man and Mammalia, which have lymphatic glands, this com¬
munication of the absorbents with the veins does not exist, except in
the glands. The statements of Lippi* concerning the communica¬
tions of the lymphatics and veins, and his representations of them,
have been shown by Fohmann (1. c. p. 4) and Panizza to be unde¬
serving of much confidence. Fohmann, however, maintains that
the veins and absorbents do communicate in the lymphatic glands,
as had been observed by J. F. Meckel, the elder, and Ph. F. Meckel, •
when injecting the absorbent vessels with mercury. I doubt very
much the existence of an open actual communication between the
lymphatics and minute veins in the glands ; and the circumstances
which induce me to doubt it are, that, when glands are injected from
their excretory duct, the small veins of the gland also frequently
become filled with the mercury, and that the cases in which this
occurred to me were always those in which the ducts had not been
well filled,—their acini not distended; and, lastly, that similar ex¬
travasation takes place from the ducts of the mammary gland into
the lymphatics of the gland, and this likewise in cases where the
acini of the mammary gland are not well injected. The coagulated
lymph in the absorbent glands resists the passage of the mercury; the
substance of the gland is lacerated; and the coats of the lymphatics
being supplied with capillaries which are continuous with veins, the
rupture of one lymphatic in the interior of a gland must be attended
with laceration of the reticulated capillary vessels and veins.
In the same manner, also, as E. H. Weber observes, fluids find
their way very easily from the branches of the pulmonary artery
into the bronchi, although no natural communication exists between
* Illustrazioni fisiologiche e pathologiche del sistema linfatieo-chillifero, etc.
Firenze, 1825.