Homology

1. A likeness, short of identity, in structure or function between parts of different structures (or systems). In the case of organisms, this may be due to evolutionary differentiation from the same or a corresponding part of a remote ancestor. Homology implies both substantial and formal analogy. Logical homology makes possible not only isomorphy in science, but as a conceptual model has the capacity of giving instructions for correct consideration and eventual explanation of phenomena.

2. A one-to-one correspondence of two coplanar geometrical figures whereby the junction lines of correspondent points are copunctal in the centre of homology and the junction points of correspondent lines are collinear on the axis of homology.