vus_, if it
is meant to express the case of origin or birth, would in Greek have been
called _gennetike_, not _genike_. Nor does the genitive express the
relation of son to father. For though we may say, "the son of the father,"
we may likewise say, "the father of the son." _Genike_, in Greek, had a
much wider, a much more philosophical meaning.(98) It meant _casus
generalis_, the general case, or rather the case which expresses the
gentus or kind. This is the real power of the genitive. If I say, "a bird
of the water," "of the water" defines the genus to which a certain bird
belongs; it refers it to the genus of water-birds. "Man of the mountains,"
means a mountaineer. In phrases such as "son of the father," or "father of
the son," the genitives have the same effect. They predicate something of
the son or of the father; and if we distinguished between the sons of the
father, and the sons of the mother, the genitives would mark the class or
genus to which the sons respectively belonged. They would answer the same
purpose as the adjectives, paternal and maternal. It can be proved
etymologically that the termination of the genitive is, in most cases,
identical with those derivative suffixes by which substantives are changed
into adjectives.(99)

It is hardly necessary to trace the history of what I call the empirical
study, or the grammatical analysis of language, beyond Rome. With
Dionysius Thrax the framework of grammar was finished. Later writers have
improved and completed it, but they have added nothing really new and
original. We can follow the stream of grammatical science from Dionysius
Thrax to our own time in an almost uninterrupted chain of Greek and Roman
writers. We find Quintilian in the first century; Scaurus, Apollonius
Dyscolus, and his son, Herodianus, in the second; Probus and Donatus in
the fourth. After Constantine had moved the seat of government from Rome,
grammatical science received a new home in the academy of Constantinople.
There were no less than twenty Greek and Latin grammarians who held
professorships at Constantinople. Under Justinian, in the sixth century,
the name of Priscianus gave a new lustre to grammatical studies, and his
work remained an authority during the Middle Ages to nearly our own times.
We ourselves have been taught grammar according to the plan which was
followed by Dionysius at Rome, by Priscianus at Constantinople, by Alcuin
at York; and whatever may be said of the improv