ANATOMY.

of the body. For there is no spot on the surface of the skin from which ointment may not be taken up, nor any internal part from which blood, when accidentally effused, may not be absorbed; nay, the very matter composing the texture of our bodies, is undergoing continual removal and renovation. These vessels must therefore be supposed to begin by open orifices generally throughout the body, although the fact can be demonstrated in the intestines only. On the inner surfaces of these organs they appear to the unaided eye fine and pointed tubes; but by the microscope their mouths are discerned to be patulous, and like a cup. The beginning absorbents soon join together, and after some time form minute vessels, capable of being injected by anatomists: these again conjoin, and form larger vessels, which are still discoverable with great difficulty.

In structure and arrangement these vessels have great similitude to veins: they have in consequence been named by some anatomists the lymphatic veins. Like the veins, their sides are thin and transparent, though of considerable strength: like the veins, they frequently communicate together, or, as it is technically termed, anastomose. The advantage derived from these communications is obvious: for by these means the dissimilar matters which they take up from various parts are mixed together, and blended with the lymph which they imbibe from the interstices of the body, and which serves as a vehicle for such heterogeneous particles; they also prevent accidental pressure made on a few vessels from obstructing the progress of the absorbed fluids, which are in that case conveyed forwards by collateral channels. Like the veins also, these tubes, by conjoining, form a tube of smaller area than the united areas of the vessels before their junction. The effect of this construction is the same as in the veins; that is, an acceleration in the currrent of the lymph in proportion as it comes nearer to the trunk of the absorbing vessels. The diameter of the thoracic duct bears but a small proportion to the united diameters of all the minute absorbents in the body, and when this duct has been opened, the lymph has flowed from it with a force and jet like that with which the blood issues from a large vein. Like the veins, the absorbents are furnished with numerous valves, which prevent any retrogade motion of their fluids, and also prevent any portion of the vessel from sustaining the weight of

more fluid than is contained between its
valves. The absorbents, however, differ
from the veins in one very material circum-
stance, viz. that they have a power of con-
Whoever reflects on
traction, and are able of themselves to pro-
the phenomena of absorption, can scarcely
pel their contents.
doubt that these vessels have a contractile
power, by which they refuse admission to
noxious substances, whilst they readily im-
sels are observed in the mesentery, when
bibe those that are salutary. If these ves-
will disappear in a certain tract, and again
turgid with absorbed chyle, their contents
become visible; a phenomenon, that can
to contract at that part, and urge forwards
only be explained by supposing the vessel
its contents. Haller found that the thoracic
there can be little doubt of these vessels
duct contracted when stimulated, so that
being muscular throughout their whole ex-

tent.

:

The absorbents are found in considerable numbers under the skin of the extremities; and, when they arrive at the groin about the size of small beans, which are and armpit, they pass through little bodies vessels, as they approach the gland, genecalled lymphatic glands. The absorbent terminate in that body and again, about rally separate into several branches, which an equal number of absorbents emerge from the gland, conjoin, and form one or more principal absorbing vessels. The absorbents, which enter the gland, are usually dego out of it, vasa efferentia. If quicksilver nominated vasa inferentia, and those, which be poured into the former vessels, the gland swells, and a great deal of quicksilver wards, if the power propelling the injection appears to be deposited in it; and afterbe continued, it is seen coming out of the gland, by the vasa efferentia. It seems therefore to follow, that the progress of the absorbed fluid is checked a little in these glands, and it is probable, that some change is effected in its progress through them. This opinion is confirmed by observing, that these glands abound with blood-vessels, which probably pour some fresh animal juices into those which are contained in the lymphatic vessels.

The lymphatic glands are found in great numbers in the groin, armpit, and side of to the absorbents of the head and extremithe neck, apparently serving like barriers the trunk. The absorbents of the intesties, as they approach to the large veins of tines, which contain the chyle, a scarcely

animalized fluid, sometimes pass through three or four sets of glands, before they arrive at the thoracic duct; hence they are called lacteal vessels primi, secundi, tertii, or quarti generis. The place where the lacteals conjoin, and meet with the lymphatics from the lower parts of the body, to form the thoracic duct, appears in animals like a reservoir, and has been named the receptaculum chyli. The vessel thus formed, penetrates the diaphragm, in conjunction with the aorta, and is called the thoracic duct. In this situation it lies close on the back bone, between the vena azygos and the aorta. Towards the neck, it leaves the bone to reach the left subclavian vein, into which its contents are poured; the absorbents of the left arm and side of the head having previously joined it. The passage of blood from the vein into the duct is effectually precluded by means of valves.

The absorbents of the right arm and side of the head form a smaller trunk on the right side, which opens into the corresponding part of the right subclavian vein.

hind the peritoneum, in that part of the ab. domen, termed the lumbar region, where they are surrounded by a quantity of loose cellular and adipous substance. Their form resembles pretty exactly that of the kidney bean. There seems to be a small part as it were scooped out, opposite to the bodies of the vertebræ; at this, which is called the notch of the kidney, the bloodvessels enter.

When we make a cut through the substance of this organ, it is found to be made up of two substances, differing in appearance. The exterior is called the cortical or arterial part, the interior, which consists of several conical portions, is named the uriniferous. The latter remains perfectly white, if a kidney be injected. Several very minute converging tubes are seen running through the uriniferous portion, and terminating by open mouths on their conical points; these, which can be filled with minute injection from the arteries, and the open mouths of which can be seen with the aid of a small magnifying power, Thus all the old materials of the body, are the excretory tubes, or tubuli urinifewhich the absorbents are continually re- ri, of the kidney. The uriniferous portion moving, all the new matter imbibed from of the gland forms about fifteen conical the surface, all the redundant lymph taken projections, termed papillæ; on each of up from the interstices of the body, and all which the excretory tubes open in great the chyle occasionally obtained from the numbers. The papillæ project into short bowels, are conveyed into the large veins membranous canals, called infundibula ; near the heart. It is, in short, chiefly by and these terminate in a common receptathis system of vessels, that the blood is aug-cle, situated at the notch of the kidney, mented in quantity, or altered in quality; they replenish the body with nutriment, and occasionally taint it with infection.

It is sufficient to inform the reader, that these vessels exist in great numbers in all parts of the body, without entering into any detailed description of their particular distribution. We may just observe, that the course of these vessels, and their entrance into glands, become occasionally demonstrated in disease. When irritated by any local mischief, they form red streaks, manifest on the surface of the body; and the irritating or poisonous nature of the matters, which they imbibe, causes swelling and inflammation of the glands, in which this matter is deposited. Thus the glands in the groin swell from the absorption of venereal matter; those in the axilla become affected in cancer, and in the inoculation for the small pox.

OF THE URINARY ORGANS,

The urine is secreted in two large glands, called the kidnies. These are situated be

and known by the name of the pelvis. From this, a canal about equal in size to a writing quill, the ureter, conveys the secreted fluid into the bladder.

The bladder is a membranous and muscular reservoir, receiving the urine as it is found in the kidneys, retaining it until it has accumulated in some quantity, and then expelling it through a canal, called the urethra.

The internal surface of the bladder is formed by a smooth membrane, constantly covered with a mucous secretion, which defends it from the irritating effects of the contained fluid. It has a muscular coat, sometimes described as a muscle, under the name of detrusor urinæ; and that part of the fibres, which is situated round the opening of the urethra, is called the sphincter vesicæ, as it keeps the aperture constantly closed until we make an effort for the expulsion of the contained fluid. The ureters open into the lower part of the bladder; and open in such a manner, that, although the urine flows readily from them into the receptacle, none can return. They

pass between the muscular and internal tunics, before they penetrate the latter.

The bladder is situated just behind the ossa pubis; and is partly covered by the peritoneum. The urethra proceeds from its lower and anterior surface, and this part is called the neck of the bladder; it then goes under the arch of the pubis. It forms in the female a canal about an inch and a half, or two inches long, which opens in the cavity, left between the labia pudendi. In the male it is about nine inches in length, and runs along the under part of the penis to the extremity of that organ, where it opens.

ORGANS OF GENERATION.

The parts which the two sexes perform, in the important business of propagating the species, are so entirely different, that we shall not be surprised at finding that the male and female organs of generation are wholly dissimilar to each other.

The germs or rudiments of the future
beings are produced by the female, in or-
gans called the ovaria. But these remain
inert and useless, unless called into action
by the fecundating influence of the male.
The fecundating fluid is prepared in two
glands, called the testes. When the germ
has been acted on by this fluid, it passes
through a canal called the fallopian tube,
into the uterus, where it is retained until
it has acquired a considerable magnitude;
and from which it is expelled at the end of
nine months. The seminal liquor of the
male is poured into the urethra, and is in-
troduced by means of the penis into a
membranous cavity of the female, called
the vagina.

External parts of generation in the female.
Over the surface of the pubis, there is a
greater accumulation of fat and cellular
substance, than in the male; and the pro-
minence caused by this structure is called
mons veneris. A longitudinal cavity ex-
tends from this eminence in front to the
anus behind; and the sides of it are
bounded by two folds of the skin, called
labia pudendi, or alæ majores. The whole
of these parts taken together constitute
the pudendum, or sinus pudoris.
mons veneris, and the outer surface of the
labia, are covered with hair to a greater or
less extent.

The

The parts contained within this longitudinal cavity are covered by a more delicate kind of integments, than that which composes the general surface of the body. A

change takes place in the organization of
the skin, somewhat similar to that which is
observed at the lips. Hence the surface of
the parts contained within the labia has a
red, smooth, and soft covering; which is
besmeared with a sebaceous secretion of
peculiar odour, furnished by numerous small
glands, lying just under the surface. This
unctuons matter is required in order to de-
fend the parts from the urine; and also to
obviate the effects of that rubbing on each
other, which must be occasioned by the
motions of the body.

Towards the upper part of the longitudi-
nal slit, left between the labia, a small pro-
minent organ is discerned, called the cli-
toris. This exactly resembles the male
penis in structure. It only projects how-
ever, about a quarter of an inch. We dis-
tinguish in it a glans and preputium, which
same name in the male.
resemble, on a small scale, the parts of the

Below the clitoris are two small folds,
called the nymphæ. These are connected
above, to the preputium clitoridis; they
below. They vary much in size; in a na-
diverge from each other, as they extend
inch at the broadest part. They are of a
tural state they may measure about half an
much greater magnitude in the Hottentot
female, and have given rise to the reports
vered in those persons by a curtain, or apron
of travellers, that the sinus pudoris is co-
of skin. About three quarters of an inch
below the clitoris, we meet with a round
female urethra: and just below this is the
aperture, which is the termination of the
opening of the vagina; which opening is
has a very different appearance in a young
In the lat-
technically called os externum uteri. This
girl, and in a married woman.
ter it is a large and free aperture, fully ade-
in the former it is shut up in a great mea-
quate in size to the admission of the penis;
sure by a thin membrane, called the hymen.
This closes the lower portion of the os ex-
ternum, to various extents in different sub-
jects; and it is torn and destroyed by the
consummation of marriage. Some little
excrescences, supposed to be the remains
of the ruptured hymen, are called carun-
culæ myrtiformes. The anus is found about
one inch behind the commencement of the
vagina.

The vagina, or canalis uteri, is a membranous canal, about five inches in length, the os externum. Its sides are dense and extending almost directly backwards from tough; and the surface is covered with nu