The thymus gland, in the chest, is very large in the feet's ; it gradually shrinks after birth, until it entirely disappears. Its use is nnknown.
The pupil of the eye is shut until the seventh or eighth month, by a thin pelli cle called membrana pupillaris. As a ge neral observation, the eye and ear are very perfect at the time of birth, and almost as large as they ever will be. (N, B. This does not apply to the external ear.) The small intestines have no valvular conniventes. The large are filled with a dark green mucous and semifluid sub stance, called mcconium. The liver is of an immense size, and fills two-thirds of the belly.
The renal capsules are very large, equal indeed to the kidnies themselves. Their use is unknown.
The testicle is placed originally in the abdomen, near the kidney ; but it passes into the scrotum towards the latter periods of gestation. Sometimes it does not descend on one or both sides till af ter birth, and sometimes not even during life.
Of the Uterus and its Contents in the earlier Months of Pregnancy.
The conception at first is lodged en tirely in the fundus uteri; and no part of it extends into the cervix ; which, on the contrary, remains contracted and hard, and filled with a tough and firm jelly. The neck, however, is gradually distend ed, so that at last there is no distinction between it and the fundus.
The corpus litteurn is larger and more vascular, and contains a cavity filled with fluid.
There is a small membraneous bag placed on the outer surface of the amnion, and connected to the navel-string, called the vesicula umbilicalis.
The chorion is at first covered all over with fine shaggy and floating processes, which are continuations of the umbilical vessels. By these it adheres to the de cidua, and derives its nourishment and supply. These processes are the fatal portion of the placenta at that time. As the ovum increases they disappear from the general surface of the chorion, be come confined to one part, and form the fleshy part of the placenta.
The decidua is most manifest in the early state of conception, and is thickest at that time. It adheres to the uterus by numerous fine flocculent processes. It is formed by the uterus previously to the entrance of the ovum into its cavity ; and is even formed in cases of extra uterine foetus, where the ovum never enters the uterus.
The placenta does not exist in a very young ovum. The whole outer surface of the chorion is covered with shaggy vessels. In the course of a few weeks one half of the membrane becomes smooth, the remainder being covered as before. These vessels, at their floating extremities, are covered with decidna ; and these parts, which at first are separa ble, gradually become intimately connect ed, and form a firm mass adhering to the uterus, which is the placenta.
The navel-string is not visible till to wards the sixth or seventh week.
The fa:tus is discernable about the fourth week after conception. In a par ticular instance, a very small fetus was discernable, where, from peculiar cir cumstances, the conception was clearly ascertained to he twenty-two days old.
Towards the end of the second month it consists of two oval masses, the head and trunk ; of which the former is bent forwards upon the chest ; the eyes are very conspicuous, and form large black prominences ; the mouth and tongue are discernible ; the body forms a larger and longer oval than the head, with the low er part of the spine curved towards the belly: the upper extremities sprout out from each side of the chest ; and the lower from the lower part of the trunk, being considerably smaller than the up per.
FOG, or MIST, a meteor consisting of gross vapours, floating near the surface of the earth. See METt:naoLocr.