ASEPTIC.--Free from injurious bacteria. ASPHYXIA.--The extreme condition caused by lack of oxygen in the blood, brought about by interrupted breathing. ASSIMILATION.--The process by which living creatures digest and absorb nutriment so that it becomes part of the substance composing them. ATROPHY.--To waste away. AUTO-INTOXICATION.--Poisoning by material formed within one's body. BACTERIA (the plural of bacterium).--Exceedingly minute, spherical, oblong, or cylindrical cells which are concerned in putrefactive processes. Some varieties cause disease. BACTERIAL DECOMPOSITION.--Putrefaction brought about by the action of bacteria. BIOLOGY.--The science which deals with the phenomena of life. BIRTH-CANAL.--The passage through which the child enters the world. It is composed of the uterus and the vagina, and is surrounded by the pelvic bones. BLADDER.--A thin, distensible sack acting as a reservoir for the urine between the time it is secreted by the kidneys and leaves the body. BREECH.--The buttocks. CESAREAN OPERATION.--The operation by which the child is taken out of the uterus by an incision through the abdominal wall. CALORIE.--The unit ordinarily employed by scientists to measure heat. CAPILLARIES.--The minute blood vessels which form a network between the terminations of the arteries and the beginnings of the veins. CARBOHYDRATE.--Any one of a group of chemical substances of which starch and sugar are the most familiar members. CARBONIC ACID GAS.--An animal waste product eliminated in the breath. In daylight plants absorb it energetically from the atmosphere through their leaves, and decompose it, assimilating the carbon, and returning the oxygen to the air. CARTILAGE.--A firm, elastic tissue; gristle. From this material many of the bones develop. CATHETERIZE.--To empty the bladder by means of a tube-like instrument which is introduced into the passage through which the urine normally leaves the bladder. CELL.--One of the microscopical structural units which make up our bodies. CELL-DIVISION.--The process by which a single cell becomes two cells. CEREBRUM.--The portion of the brain which is the seat of mental activity. CHORIONIC MEMBRANE.--The outermost of the two membranes which surround the embryo. CHROMATIN.--A substance within the nucleus of a cell which has a special affinity for certain staining agents. CHROMOSOMES.--One of the pieces into which the chromatin is broken during the act of cell-division. CLINICAL.--Pertaining to the sick-bed. COLOSTRUM.--The fluid secreted by the breasts during pregnancy and for two or three days after the birth of the child. CONTRACTION.--The act by which the muscle fibers of the uterus become shorter and press upon its contents. CURETTAGE.--Scraping out the lining of the uterus. DELIVERY.--The birth of the child. DIAGNOSIS.--The determination of either normal or abnormal states of the body. DIAPHRAGM.--The muscular partition between the chest and the abdomen.