ood current. It is, as it were, in too crude a state, and
needs some special preparation.

The intestines are suspended to the posterior wall of the abdomen by a
double fold of peritoneum called the mesentery. In this membrane are
some 150 glands about the size of an almond, called mesenteric
glands. Now the lacteals join these glands and pour in their fluid
contents to undergo some important changes. It is not unlikely that the
mesenteric glands may intercept, like a filter, material which, if allowed
to enter the blood, would disturb the whole body. Thus, while the glands
might suffer, the rest of the body might escape. This may account for the
fact that these glands and the lymphatics may be easily irritated and
inflamed, thus becoming enlarged and sensitive, as often occurs in the
axilla.

Having been acted upon by the mesenteric glands, and passed through them,
the chyle flows onward until it is poured into a dilated reservoir for the
chyle, known as the receptaculum chyli. This is a sac-like expansion
of the lower end of the thoracic duct. Into this receptacle, situated at
the level of the upper lumbar vertebrae, in front of the spinal column, are
poured, not only the contents of the lacteals, but also of the lymphatic
vessels of the lower limbs.

158. The Thoracic Duct. This duct is a tube from fifteen to eighteen
inches long, which passes upwards in front of the spine to reach the base
of the neck, where it opens at the junction of the great veins of the left
side of the head with those of the left arm. Thus the thoracic duct
acts as a kind of feeding pipe to carry along the nutritive material
obtained from the food and to pour it into the blood current. It is to be
remembered that the lacteals are in reality lymphatics--the
lymphatics of the intestines.

[Illustration: Fig. 61.--Section of a Lymphatic Gland.

A, strong fibrous capsule sending partitions into the gland;
B, partitions between the follicles or pouches of the _cortical_ or
outer portion;
C, partitions of the _medullary_ or central portion;
D, E, masses of protoplasmic matter in the pouches of the gland;
F, lymph-vessels which bring lymph _to_ the gland, passing into its
center;
G, confluence of those leading to the efferent vessel;
H, vessel which carries the lymph away _from_ the gland.
]

159. The Lymphatics. In nearly every tissue and organ of the body
there is a marvelous network of vessels, precisely like the l