" In the first month," says Blandin, " it seems to contract, and its walls to fall in upon themselves; but afterwards opposite changes take place. By reason of the resistance offered by the pelvis, when the uterus begins to in crease, and especially when it has acquired a certain size, it makes, as it were, a protrusion upwards, and is carried into the part of the abdominal cavity, which it dilates, especially in front, in consequence of which the obliquity of the axis of that cavity for wards is diminished. The dilated uterus is placed entirely in front, behind the anterior abdominal wall, and presses the small intestine and omentum towards the spine : the omen tum, however, is sometimes, though rarely, found in front of the uterus. The diaphragm is also pushed upwards and raised as high aS the level of the sixth dorsal vertebra : all the peritoneal folds of the uterus are obliterated ; the peritoneum no longer descends into the pelvic excavation, the bladder and the rectum are strongly compressed, and are in some de gree impeded in performing their functions; the uterus itself is inclined to one side, in con sequence of the projection of the vertebral column, and generally to the right side, which, according to Chaussier, is attributable to the greater shortness of the round ligament of the right side. Notwithstanding all this enlarge ment of the abdominal cavity, the viscera are compressed more strongly than usual, and can become protruded with greater facility, when the distended and attenuated walls have lost much of their power of resistance. The nor mal irritation of which the uterus is the seat, causes a greater afflux of blood into the whole inferior part of the vascular system, and into its own vessels in particular."' During the development and growth of the walls of the abdominal cavity some interesting changes are observed to take place in its shape, capacity, and in the positions of the contained viscem. The most remarkable characteristic of the abdomen at the earliest period is its very great capacity when compared with the other ca vities ; this arises from the great development of its contained organs. This great size, however, is manifest entirely in die umbilical region, for neither the epigastric nor the hypogastric can be said to exceed their proportional magnitude in the adult. On the contrary, both these regions are proportionally much smaller than in the adult; the epigastric, in consequence of the contracted diameters of the thorax, but more particularly in consequence of the small size of the vault which is formed by the di-aphragm ; and the hypogastric by reason of the imper fectly developed state of the pelvis. Hence, then, we find that most of the viscera extend more or less into the middle or umbilical region, which thus exhibits a very great en largement. The liver is the viscus which exhibits the most remarkable degree of enlarge ment; its two lateral lobes present but little difference in size, it extends laterally so as to occupy nearly the whole epigastrium, leaving but a small space at the left side for the stomach and spleen ; it passes considerably beyond the inferior margin of the ribs, so that a great portion of it is found in the umbilical region, extending. even to the hypogastrium. This great extent of space occupied by the liver -necessarily causes corresponding altera tions in the positions of the neighbouring vis cera, and of none more than the,stomach. The direction of this organ is nearly perpendi cular, its pyloric extremity is found a little to the right in the umbilical region, while the aspect of its splenic end is upwards and to the left; its great curvature looks to the left side and downwards, and its lesser cur vature to the right and upwards. The spleen is not altogether contained in the left hy pochondrium, but also extends into the left lumbar region, and may be felt below the false ribs. The duodenum does not change its positive situation with reference to the spine, but, in consequence of the position of the stomach, its curves are more marked, the superior portion passes more decidedly up wards, and the whole duodenum is to a greater extent covered by the stomach. The rest of the
small intestine is crowded backwards against the spine, and in consequence of the non-deve lopment of the pelvis is found entirely in the umbilical region; nor is it covered by the omentum, which as yet has attained but a very small size. At this early period, moreover, the bladder is an abdominal viscus; in general, very capacious and of a cylindrical form, it extends out of the pelvis to within a very short distance of the umbilicus, to which it is con nected by the urachus, so that it occupies a considerable portion of the hypogastric and a small part of the u mbili cal regions ; consequently. as Portal remarks, the shortest route by which the bladder can be reached at this early age is according to the method of the suprapubic operation, and it is only a small portion of the neck of the bladder which is at all in relation with the perinwum. A considerable portion of the rectum, also, is found in the hypogastrium, and in the female the uterus and ovaries and the Fallopian tubes. Prior to the seventh or eighth month of intra-uterine life, when the tes ticles enter the scrotum, they are found suc cessively as they descend in different regions of the abdominal cavity, at first in the lumbar regions immediately beneath the kidneys, and then at different heights along the inner side of the iliac fossce ; we also observe here that pro cess of peritoneum connected with the testicle, and extending from it to the inguinal canal, which is known by the name of the diverticu lunz of Nuck : a similar process exists in a much less developed condition in the female connected with the round ligament. The prin cipal difference observable, as regards the large intestine in the fcetus at its full period, consists in the great curvature of that portion of it that is found in the left iliac region, occasioned by the narrowness of the pelvis admitting but a small part of the rectum.'f' In the progressive development which takes place during intra uterine life, the position of this as well as of the other portions of the intestinal canal presents dif ferences Which it does not belong to the present article to examine. (See INTESTINAL CANAL.) The capacity of the abdominal cavity and the position of some of its contained organs, as they thus exist in the fcetus at its full period, continue pretty nearly the same for some time after birth. The enlargement, however, of the vault of the diaphragm increases the capacity of the epigastrium, while the gradual diminu tion of the liver affords room for the passage of more organs from the umbilical region up wards, and the stomach is allowed to take a more horizontal direction. These changes, which are gradual in the periods of life prior to puberty, become most manifest when the arrival of that period gives rise to the enlarge ment of the pelvis ; then the umbilical region is as it were relieved from its overloaded state ; the belly is less prominent, for the bladder now occupies its proper place in the pelvic cavity; the rectum, too, sinks into it, and many of the convolutions of the small intestine are found in it: thus, by the enlargement of the hypochondria in the first instance, and subse quently by the development of the pelvis, the three subdivisions of the abdominal cavity assume those proportions in their respective magnitudes which are characteristic of the adult period.
In considering the probable amount of in jury inflicted by wounds which may have pene trated the abdominal cavity, we must take into account the changes which the different atti tudes of the body occasion in the positions of the viscera. These changes cannot be exten sive, and only regard the position of each viscus with reference to the whole cavity, the relations of that viscus to the neighbouring ones being unaltered, or nearly so. They take place in obedience to the law of gravitation, and it is so easy, by a little reflection, to de duce what the changes must be, keeping in mind the various means made use of to limit and prevent displacement, that it seems unne cessary to do more here than allude to the fact that the viscera are altered in position under the influence of such a cause.