Compensatroy Hypertrophy. Growth or increase in size of residual part of a tissue or organ, some of which has been removed or put out of action, e.g. when one kidney is removed the other enlarges.

Complement. A group of proteins (enzymes or enzyme-precursors) normally present in the blood of vertebrates, forming a complex system that takes an essential part in the lethal action (lysis) of antibody on bacteria and other cells. Activity of complement system is rapidly destroyed by heat. Complement often disappears from serum in which an antigen-antibody reaction has occurred: this complement fixation can be to test for presence of an antigen or an antibody, and is the basis of the Wasserman test for syphilis.

Complemental Males.
Males which live attached to females, and are usually small and more or less degenerate, except for reproductive organs; found in e.g. certain Crustacea, angle-fish.

Compound eye. The eye of insects and crustaceans, which consists of numerous visual units, the ommatidia. Each ommatidium consists of a leans beneath which is a crystalline cone and light-senstitive cells. The eye is convex, with the apices of the cones converging on to the optic nerve.
There are two type of compound eye. In apposition eye typical of diurnal insects, each ommatidium focuses rays parallel to its long axis so that each gives an image of a minute part of the visual field, producing a detailed mosaic image. In superposition eyes, typical of nocturnal insects, each ommatidium receives light from a larger part of the visual field and the image may overlap with those received by many neighbouring ommatidia. This produced an image that is bright but lacks sharpness of detail.

Compound leaf. If the incision touches the mud rib and divide the leaf into various segments then it is called a compound leaf. The segment are known as leaf lets.

Compound tissues.
A collection of two or more different types of simple tissues that help in the performance of a common function are called compound tissues e.g. xylem and phoem in vascular plants.