Allen and Greenough's New Latin Grammar for Schools and Colleges
J. B. Greenough, G. L. Kittredge, A. A. Howard, Benj. L. D'Ooge, Ed.

The variety in form in the Nominative is due to simple modi fications of the stem, of which the most important are—

1. Combination of final consonants: as of c (or g ) and s to form x; dux , ducis , stem duc-; rēx , rēgis , stem rēg-.
2. Omission of a final consonant: as of a final nasal; leō , leōnis , stem leōn-; ōrātiō , ōrātiōnis , stem ōrātiōn-.
3. Omission of a final vowel: as of final i; calcar , calcāris , stem calcāri-.
4. Change of vowel in the final syllable : as of a toe; prīnceps (for -caps), prīncipis , stem prīncip- (for -cap-).

CONSONANT STEMS

Mute Stems