Life may be one of health or one of disease. Biology treats of organized beings under their diverse relations, their organic structure, life, growth, action and reproduction. I desire to give you some of the important principles of biology as observed from several view points, confining myself to the physiological branch which treats of the functions of the human body. You may accuse me of repetition. Fleeting impressions are only veneered.
Essential ideas are worthy of repetition.
It is that quality which distinguishes a living animal or plant from an inorganic body, from one which does not live, whose movements are not determined by an intelligence. Life consists of actions guided by intelligence. Life may consist of too much elastic force, too great or a lack of resisting vigor, such a condition is known as disease. An organized being is one which is composed of organs. An organ is that which has a particular function to perform.