m, _material_, as well as
materia, materiam.

b) Fames, _hunger_, regularly of the Third Declension, has the Abl. fame
of the Fifth.

c) Requies, requietis, _rest_, regularly of the Third Declension, takes
an Acc. of the Fifth, requiem, in addition to requietem.

d) Besides plebs, plebis, _common people_, of the Third Declension, we
find plebes, plebei (also plebi, see Sec. 52, 2), of the Fifth.

Heterogeneous Nouns.

60. Heterogeneous nouns vary in Gender. Thus:--

1. Several nouns of the Second Declension have two forms,--one Masc. in
-us, and one Neuter in -um; as, clipeus, clipeum, _shield_; carrus, carrum,
_cart_.

2. Other nouns have one gender in the Singular, another in the Plural;
as,--

SINGULAR. PLURAL.
balneum, n., _bath_; balneae, f., _bath-house_.
epulum, n., _feast_; epulae, f., _feast_.
frenum, n., _bridle_; freni, m.(rarely frena, n.), _bridle_.
jocus, m., _jest_; joca, n. (also joci, m.), _jests_.
locus, m., _place_; loca, n., _places_; loci, m., _passages
or topics in an author_.
rastrum, n., _rake_; rastri, m.; rastra, n., _rakes_.

a. Heterogeneous nouns may at the same time be heteroclites, as in case
of the first two examples above.

Plurals with Change of Meaning.

61. The following nouns have one meaning in the Singular, and another in
the Plural:--

SINGULAR. PLURAL.
aedes, _temple_; aedes, _house_.
auxilium, _help_; auxilia, _auxiliary troops_.
carcer, _prison_; carceres, _stalls for racing-chariot_.
castrum, _fort_; castra, _camp_.
copia, _abundance_; copiae, _troops_, _resources_.
finis, _end_; fines, _borders_, _territory_.
fortuna, _fortune_; fortunae, _possessions_, _wealth_.
gratia, _favor_, gratiae, _thanks_.
_gratitude_;
impedimentum, impedimenta, _baggage_.
_hindrance_;
littera, _letter_ (of the litterae, _epistle; literature_.
alphabet);
mos, _habit_, _custom_; mores, _character_.
opera, _help_, _service_; operae, _laborers_.
(ops) opis, _help_; opes, _resources_.
pars, _part_; partes, _party_; _role_.
sal, _salt_; sales, _wit_.

* * * * *

B. ADJECTIVES.

62. Adjectives denote _quality_. They are declined like nouns, and fall
into t