Earlier Inflection (including Caesar and Cicero).
          Servos, m., Aevom, n., Equos, m.,
          slave. age. horse. 
                        SINGULAR.
  Nom. servos aevom equos
  Gen. servi aevi equi
  Dat. servo aevo equo
  Acc. servom aevom equom
  Voc. serve aevom eque
  Abl. servo aevo equo

Later inflection (after Cicero).
SINGULAR.
Nom.  servus          aevum           equus
Gen.  servi           aevi            equi
Dat.  servo           aevo            equo
Act.  servum          aevum           equum
Voc.  serve           aevum           eque
Abl.  servo           aevo            equo

1.  The Plural of these nouns is regular, and always uniform.

Peculiarities of Inflection in the Second Declension.

25. 1.  Proper names in -ius regularly form the Genitive Singular in -i (instead of -ii), and the Vocative Singular in -i (for -ie); as Vergili, of Virgil, or O Virgil (instead of Vergilii, Vergilie).  In such words the accent stands upon the penult, even though that be short.  Nouns in -ajus, -ejus form the Gen. in -ai, -ei, as Pompejus, Pompei.

2.  Nouns in -ius and -ium, until after the beginning of the reign of Augustus (31 B.C.), regularly formed the Genitive Singular in -i (instead of -ii); as,—­

Nom.  ingenium        filius
Gen.  ingeni          fili

These Genitives accent the penult, even when it is short.

3.  Filius forms the Vocative Singular in -i (for -ie); viz. fili, O son!

4.  Deus, god, lacks the Vocative Singular.  The Plural is inflected as follows:—­

Nom. di (dei) Gen. deorum (deum) Dat. dis (deis) Acc. deos Voc. di (dei) Abl. dis (deis)

5.  The Locative Singular ends in -i; as, Corinthi, at Corinth.

6.  The Genitive Plural has -um, instead of -orum,—­

  a) in words denoting money and measure; as, talentum, of talents;
  modium, of pecks; sestertium, of sesterces.

  b) in duumvir, triumvir, decemvir; as, duumvirum.

  c) sometimes in other words; as, liberum, of the children; socium, of
  the allies.

Exceptions to Gender in the Second Declension.

26. 1.  The following nouns in -us are Feminine by exception:—­

  a) Names of towns, islands, trees—­according to the general rule laid
  down in Sec. 15, 2; also some names of countries; as Aegyptus, Egypt.

  b) Five special words,—­