.ABDIEL, (Hob. 'Owl, servant + god). In Paradise Lost. the faithful angel who ;pnosed the revolt in heaven begun by Satan. ABDOMEN. The lower cavity of the human body. The trunk of the human body is divided by the diaphragm into two eavities—the upper being the the or chest. and the lower the abdomen or belly. Both the cavity and the viscera it contains are included in the term abdomen. It contains the liver, pancreas, spleen, and kidneys, as well as the stomach, small and large intestine. The lower bowel, the bladder. and internal organs of generation lie in the lowest part of the cavity. which is called the pelvis. The abdomen is lined by a serous membrane, the winch is folded over the viscera, allowing, them a certain freedom of motion, hut keeping them in their proper relations to each other. The abdomen is divided by two imaginary horizontal lines into three principal zones—the upper or epigastrie, the middle or umbilical, and the lower or hypo pastrie. These are sulalivided by two vertical lines—the side-divisions being called the hypochondriac, lumbar, am' iliac regions respe• tively: the names epigastrie and umbilical are then applied in a restricted sense to the middle divisions of the two upper zones. while the
middle division of the lower is called the hypo gastric region. The abdominal viscera are sub jeet to many important acute and chronic affec tions, to which reference is made tinder their respect i VI' headings.
Anoomux. In entomology, the last of the three parts into which the body of an insect is divided. It is composed of a number of rings or segments, frequently nine, more or less distinct from each other. It eontains a portion of the intestines and the sexual organs. In the pet-feet insect, its segments bear inn legs or wings: hut the hind legs of lave or caterpillars, which afterward disappear, are attached to them. In many insects, its last segments bear appendages of various uses and forms, as pincers. stings, borers or ovipositor,, etc. See ANATOMY and au thorities there referred to.