Ge"nus (jē"nŭs), n.;
pl. Genera (#). [L., birth, race, kind,
sort; akin to Gr. ?. See Gender, and cf. Benign.]
1. (Logic) A class of objects divided
into several subordinate species; a class more extensive than a
species; a precisely defined and exactly divided class; one of the
five predicable conceptions, or sorts of terms.
2. (Biol.) An assemblage of species,
having so many fundamental points of structure in common, that in the
judgment of competent scientists, they may receive a common
substantive name. A genus is not necessarily the lowest definable
group of species, for it may often be divided into several subgenera.
In proportion as its definition is exact, it is natural genus;
if its definition can not be made clear, it is more or less an
artificial genus.
☞ Thus in the animal kingdom the lion, leopard, tiger, cat,
and panther are species of the Cat kind or genus, while in the
vegetable kingdom all the species of oak form a single genus. Some
genera are represented by a multitude of species, as Solanum
(Nightshade) and Carex (Sedge), others by few, and some
by only one known species.
Subaltern genus (Logic), a genus
which may be a species of a higher genus, as the genus denoted by
quadruped, which is also a species of mammal. --
Summum genus [L.] (Logic), the highest
genus; a genus which can not be classed as a species, as
being.