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The Collaborative International Dictionary
Genera

Genus \Ge"nus\ (j[=e]"n[u^]s), 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.

    Note: 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.

Genera

Genera \Gen"e*ra\, n. pl. See Genus.

Douglas Harper's Etymology Dictionary
genera

plural of genus.

Wiktionary
genera

n. (genus English)

WordNet
genus
  1. n. a general kind of something; "ignore the genus communism"

  2. (biology) taxonomic group containing one or more species

  3. [also: genera (pl)]

genera

See genus

Wikipedia
Genera (operating system)

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments. Genera is also sold by Symbolics as Open Genera, which runs Genera on computers based on an Alpha processor using Tru64 UNIX. It is available as proprietary software.

Genera is an example of a Lisp, object-oriented operating system.

Genera supports incremental and interactive development of complex software using a mix of programming styles with extensive support for object-oriented programming.

Usage examples of "genera".

We may instance Rubus, Rosa, and Hieracium amongst plants, several genera of insects, and several genera of Brachiopod shells.

Fresh-water and salt-loving plants have generally very wide ranges and are much diffused, but this seems to be connected with the nature of the stations inhabited by them, and has little or no relation to the size of the genera to which the species belong.

Moreover, on the view of the origin of genera which I shall presently give, we have no right to expect often to meet with generic differences in our domesticated productions.

I am inclined to suspect that we see in these polymorphic genera variations in points of structure which are of no service or disservice to the species, and which consequently have not been seized on and rendered definite by natural selection, as hereafter will be explained.

In most polymorphic genera some of the species have fixed and definite characters.

Under genera, including the most polymorphic forms, Mr Babington gives 251 species, whereas Mr Bentham gives only 112, -- a difference of 139 doubtful forms!

Moreover, the species of the large genera which present any varieties, invariably present a larger average number of varieties than do the species of the small genera.

Both these results follow when another division is made, and when all the smallest genera, with from only one to four species, are absolutely excluded from the tables.

Now Fries has remarked in regard to plants, and Westwood in regard to insects, that in large genera the amount of difference between the species is often exceedingly small.

In this respect, therefore, the species of the larger genera resemble varieties, more than do the species of the smaller genera.

Or the case may be put in another way, and it may be said, that in the larger genera, in which a number of varieties or incipient species greater than the average are now manufacturing, many of the species already manufactured still to a certain extent resemble varieties, for they differ from each other by a less than usual amount of difference.

In genera having more than the average number of species in any country, the species of these genera have more than the average number of varieties.

In large genera the species are apt to be closely, but unequally, allied together, forming little clusters round certain species.

In all these several respects the species of large genera present a strong analogy with varieties.

But by steps hereafter to be explained, the larger genera also tend to break up into smaller genera.