The appendix vermiformis cæci is long and of large size, and is continued directly from the central part of the cul-de-sac of the cæcum, of which it appears to be a constricted continuation. This is the character of the appendix cæci in the higher quadrumana.
The large intestines are filled with a dark-green, viscous secretion, called meconium, from its resemblance to the inspissated juice of the poppy.
The pancreas is comparatively larger in the fetus than in the adult.
The spleen is comparatively smaller in the fetus than in the adult.
FETAL LIVER.
The liver is the first-formed organ in the embryo. It is developed from the alimentary canal, and at about the third week fills the whole abdomen, and is one half the weight of the entire embryo. At the fourth month the liver is of immense size in proportion to the bulk of the fetus. At birth it is of very large size, and occupies the whole upper part of the abdomen. The left lobe is as large as the right, and the falciform ligament corresponds with the middle line of the body. The liver diminishes rapidly after birth, probably from obliteration of the umbilical vein.
KIDNEYS AND SUPRA-RENAL CAPSULES.
The kidneys present a lobulated appearance in the fetus, which is their permanent type among some animals, as the bear, the otter, and cetacea.
The supra-renal capsules are organs which appear, from their early and considerable development, to belong especially to the economy of the fetus. They are distinctly formed at the second month of embryonic life, and are greater in size and weight than the kidneys. At the third or fourth month, they are equaled in bulk by the kidneys; and at birth, they are about one third less than those organs.