DIGESTIVE TRACT.--The entire alimentary canal, including the mouth, œsophagus, stomach, and the small and large intestines. DIPLOCOCCUS.--A form of coccus in which two individuals remain attached after cell division has taken place. DISINFECT.--To destroy the germs of disease. DISINFECTANT.--An agent that destroys the germs of disease. DISINFECTION.--The process of destroying the germs of disease. E EMETIC.--A substance used to induce vomiting. ENEMA.--An injection of fluid into the rectum. F FECAL.--Pertaining to feces. FECES.--Matter discharged from the bowels; bowel movement. FERMENTATION.--Decomposition produced in an organic substance by the action of certain living agents. FISSION.--The process by which a cell divides into two parts. FLAGELLUM (pl. flagella).--A long hair-like appendage, by the action of which certain micro-organisms are enabled to move. FLEX.--To bend at a joint. FOMENTATION.--See _Stupe_. G GASTRIC JUICE.--The fluid secreted by the glands of the stomach. GERM.--A minute unicellular organism, either animal or vegetable; a micro-organism; a microbe. GERMICIDE.--An agent having the power to kill germs. H HOST.--An animal or plant in or upon which another organism lives. I IMMUNE.--Not susceptible to a particular disease; also, a person who is not susceptible to a particular disease. IMMUNITY.--The state in which an individual is not susceptible to a particular disease. IMMUNIZE.--To render immune. INCUBATION.--The interval between exposure to an infectious disease and the first appearance of symptoms. INFECT.--To communicate disease germs. INFECTION.--An agent by which disease may be communicated from one individual to another; also, an infectious disease. INOCULATE.--To introduce any biological product directly into the tissues of the body. INOCULATION.--The process of inoculating. INTESTINAL TRACT.--The small and large intestines. M MICROBE.--See _Germ_. MICRO-ORGANISM.--See _Germ_. MUCUS.--The substance secreted by mucous membranes. MUCOUS MEMBRANES.--The membranes lining certain cavities of the body, especially the digestive and respiratory tracts. N NUTRIENT.--One of several chemical groups to which the essential constituents of food belong. O ORGANIC.--Derived from or relating to an organism. ORGANISM.--An individual that is or has been alive. P PARASITE.--An individual that lives in or upon another individual. PASTEURIZATION.--The process of pasteurizing. PASTEURIZE.--To subject milk to a temperature of 142°-145° Fahrenheit for thirty minutes. PATHOGENIC.--Disease-producing. PERTUSSIS.--Whooping-cough. PROTEID.--One of the complex nitrogenous substances constituting the essential parts of animal and vegetable tissues. PROTOZOÖN (pl. protozoa).--An animal organism composed of a single cell. PUS.--The fluid product of inflammation; matter.