571. Imparisyllables in #-es# or #-ēs# and substantives in #-er#, #-ō#,
#-or#, and #-ōs# are masculine: as,
#caespes#, _sod_; #pēs#, _foot_; #agger#, _mound_; #sermō#, _speech_;
#pallor#, _paleness_; #flōs#, _flower_.
572. These imparisyllables in #-es# or #-ēs# are feminine: #merges#,
_sheaf_, #seges#, _crop_, #teges#, _mat_; #requiēs# and #quiēs#, _rest_;
#compedēs#, plural, _fetters_; #mercēs#, _reward_. #aes#, _copper_,
_bronze_, is neuter.
573. These substantives in #-er# are neuter: #cadāver#, _corpse_,
#iter#, _way_, #tūber#, _swelling_, _truffle_, #ūber#, _udder_,
#verberis#, _lash_, genitive, no nominative; also names of plants in
#-er#: as, #acer#, _maple_, #cicer#, _chickpea_, #papāver#, _poppy_,
#piper#, _pepper_, #siler#, _osier_, #siser#, _skirret_, #sūber#,
_corktree_. #linter#, _tub_, _boat_, is feminine, once masculine. #vēr#,
_spring_, is neuter.
574. Substantives in #-ō#, with genitive #-inis# (485), are feminine;
as, #imāgō#, #imāginis#, _likeness_; also #carō#, #carnis#, _flesh_, and
words of action in #-iō# and #-tiō# (227, 228). But #cardō#, _hinge_,
#ōrdō#, _rank_, and #turbō#, _whirlwind_, are masculine. #margō#,
_brink_, and #cupīdō#, _desire_, are sometimes masculine.
575. These substantives in #-or# are neuter: #ador#, _spelt_, #aequor#,
_sea_, #marmor#, _marble_, #cor#, _heart_. #arbor#, _tree_, is feminine.
576. These substantives in #-ōs# are feminine: #cōs#, _whetstone_,
#arbōs#, _tree_, #dōs#, _dowry_. #ōs#, #ōris#, _mouth_, _face_, is
neuter, also #os#, #ossis#, _bone_.
[Erratum:
575 ... #cor#, _heart_.
. missing]