Homology

[Gr. homolog i a, agreement.] State or quality of being homologous or correspondent; relation; affinity. ( Anat .) A term used to indicate structural correspondence, while the term analogy is employed to indicate functional resemblance. Thus, by homologue is implied "the same organ in different animals, under every variety of form and function;" while by analogue we understand "a part or organ in one animal which has the same functions as another part or organ in a different animal." For example, the wings of an insect are the analogues of those of a bat or bird, but not the homologues; while the latter are homologues with the arms of man, fore-legs of quadrupeds, and the pectoral fins of fishes.