Antigens are the substances which produce the antibodies in the blood and body fluids. These are merely terms used to designate the mechanism of immunity.
Saprophytes
Saprophytes are microscopic organisms which feed upon dead organic matter. A saprophyte is a vegetable organism.
Obligate Saprophytes
Obligate saprophytes are saprophytes which can not be made to develop under any circumstances in living tissue, but will develop in dead tissue in which they produce toxins. The diphtheria and tetanus bacilli develop in a localized area of dead tissue and produce the toxins peculiar to this condition.
Septicemia
Septicemia is a condition wherein so-called pathogenic bacteria and their accompanying poisons are present in the blood. These bacteria may develop within the blood or they may be carried into the blood from some local point where they are developing due to the condition of the tissues as a result of interference with transmission of mental impulses.
Toxemia
Toxemia is a condition caused by the absorption of toxins from the bacterial activity. This is commonly known as blood poisoning.