[110]. Only vowels which are short and atonic may be lost. The loss of a medial vowel is called Syncope; of an initial vowel, Aphaeresis; of a final vowel Apocope.
[111]. Syncope. ([a.]) Loss of a posttonic vowel, entailing the loss of a syllable, occurs in ardus (Lucil.; for ă see [128]) for the common āridus, dry; caldus by the side of calidus, warm (Quint. 1, 6, 19); reppulī, I pushed back, and rettulī, I carried back, stand for *répepulī and *rétetulī ([861]); pergō, I proceed, stands for *perregō from regō (cf. cor-rigō, ē-rigō, where the e is weakened, [103], and porrigō, porgō, where it is either weakened or lost), hence it forms its perfect perrēxī ([953]): pōnō, I place, is for *posnō ([170, 2]) from *po-sinō ([112]), hence it forms its past participle positus ([972]); for iūrgō, I blame. Plautus has iūrigō; *ūsūripō (from ūsus and rapere) yields ūsurpō, I utilize; *gāvideō, hence gāvīsus ([801]), gives gaudeo, I rejoice, converting āṷ to aṷ before the following d ([128]); in a similar way auceps, bird-catcher, is formed from *aviceps (avis, bird, and capere, catch); claudere, lock, from *clāvidere (clāvis, key); aetās, age, for áevitās ([262]); praecō, herald, for *práevicō ([105, g]) prae-vocō ([211]); also with change of ou to ū ([100]), prūdēns, prudent, for *proudēns from providēns, foreseeing; nūper, lately, from *noviper; nūntius, messenger, from *noventius ([333]); iūcundus, joyful, from iuvicundus (Cic. Fin. 2, 14). But forms like pōclum, cup, saeclum, age, do not belong here, as they are original and not derived by syncope from pōculum, saeculum; cf. [172].
([b.]) Where, through the loss of a vowel, l or r would come to stand between two consonants, or where they would be final and preceded by a consonant, l and r become syllabic ([83]) and the syllable is thus maintained. Syllabic l is represented by ul, syllabic r by er ([172, 3]). The development of such intercalary vowels as u before l and e before r is called Anaptyxis ([172]). Thus, *sacri-dōts (cf. sacri-legium) became first *sacr̥dōts by syncope, then sacerdōs, priest, by anaptyxis; *ācribus (cf. ācri-mōnia, pungency) first became *ācr̥bus then ācerbus, pungent; *agrilos ([267], cf. agri-cola, farmer) became first *agr̥los, then *agerlos, and finally, by assimilation of the r to l ([166, 7]), agellus, small field; from *dis-ficilter (adverb from dis- and facilis) arose *difficl̥ter and difficulter, with difficulty. The nominative sg. of the following words is to be explained thus. ager ([451]) was originally *agros (cf. Greek ἄγρος), which changed successively to *agr̥s, *agers, and ager (for the loss of -s see [171, 1 and 3]). Similarly *ācris, passing through the stages of *ācr̥s, *ācers, became ācer ([627]), and *famlos by way of *faml̥s, *famuls, became famul ([455]), to which later the common ending of nouns of the o-declension was added, giving famulus.
[112]. Aphaeresis. Aphaeresis hardly occurs in literary Latin. In the pronoun iste the initial i is sometimes dropped ([667]); this loss implies an accented ultima ([94]). A trace of prehistoric aphaeresis is found in the prefix po- for *apo (Greek ἀπό) in pōnō, I place, for po-s(i)nō ([111, a]).
[113]. Apocope. Under the same conditions under which a medial vowel was syncopated, the final vowel of a word which stood in close union with the following word, as a preposition with its noun, was lost. In this way *peri (Greek περί) became per; *apo (Greek ἀπό) became ap, ab ([164, 2]); *eti (Greek ἔτι) became et. Similarly the final -e of the enclitics -ce, -ne, not, and -ne interrogative was lost: *sī-ce became sīc, so; *quī-ne, quīn, why not; habēsne, haben, hast thou; the imperatives dīc, say, dūc, lead, and fac, do, stand for earlier dīce, dūce, face ([846]); the shortened form em for eme (imperative of emere, take) has been turned into an interjection ([1149]). In the same way nec arose by the side of neque; ac by the side of atque ([158]). Final -e has also been dropped in the nominative sg. of a number of polysyllabic neuter stems in -āli and -āri ([546]): as, animal, animal, for *animāle, exemplar, pattern, for *exemplāre. See [536], [537]. It must, however, be remembered that in most of the cases given the loss of a final vowel would also result from elision ([119]) before the initial vowel of the following word.
[COMBINATION OF ADJACENT VOWELS.]
[114]. Hiatus. A succession of two vowel sounds not making a diphthong is called Hiatus.
When in the formation of words by means of suffixes or prefixes or through the loss of an intervening consonant, two vowels come into contact within a word we speak of internal hiatus; the term external hiatus comprises those cases where, in connected discourse, the final vowel of one word comes into contact with the initial vowel of the following word. For the latter kind, see [2474].
[115]. The treatment of vowels in internal hiatus is four-fold: (1.) The hiatus may remain; (2.) the two vowels may be fused into one (Contraction); (3.) one of the two vowels may be dropped (Elision); and (4.) the two vowels may be combined into a diphthong.
[116]. Hiatus is maintained ([a.]) between two adjacent vowels the second of which is long and accented (according to the classical accentuation): as, coḗgi, I forced, and coā́ctus, forced ([937]); but cōgō ([118, 3]). For coepi, instead of coḗpī, I began, see [120].