Found 1 items, similar to General homology.
English → English (gcide)
Definition: General homology
Homology
\Ho*mol"o*gy\, n. [Gr. ? agreement. See
Homologous.]
1. The quality of being homologous; correspondence; relation;
as, the homologyof similar polygons.
[1913 Webster]
2. (Biol.) Correspondence or relation in type of structure in
contradistinction to similarity of function; as, the
relation in structure between the leg and arm of a man; or
that between the arm of a man, the fore leg of a horse,
the wing of a bird, and the fin of a fish, all these
organs being modifications of one type of structure.
[1913 Webster]
Note: Homology indicates genetic relationship, and according
to Haeckel special homology should be defined in terms
of identity of embryonic origin. See
Homotypy, and
Homogeny.
[1913 Webster]
3. (Chem.) The correspondence or resemblance of substances
belonging to the same type or series; a similarity of
composition varying by a small, regular difference, and
usually attended by a regular variation in physical
properties; as, there is an homology between methane,
CH4, ethane,
C2H6, propane,
C3H8, etc., all members
of the paraffin series. In an extended sense, the term is
applied to the relation between chemical elements of the
same group; as, chlorine, bromine, and iodine are said to
be in homology with each other. Cf.
Heterology.
[1913 Webster]
General homology (Biol.), the higher relation which a
series of parts, or a single part, bears to the
fundamental or general type on which the group is
constituted. --Owen.
Serial homology (Biol.), representative or repetitive
relation in the segments of the same organism, -- as in
the lobster, where the parts follow each other in a
straight line or series. --Owen. See
Homotypy.
Special homology (Biol.), the correspondence of a part or
organ with those of a different animal, as determined by
relative position and connection. --Owen.
[1913 Webster]