Pliny recited his speeches before delivering them, and subsequently
published them, sometimes with additions.
_Ep._ vii. 17, 2, 'Miror quod scribis fuisse quosdam qui
reprehenderent quod orationes omnino recitarem.'
_Ep._ iii. 18, 1 (of the _Panegyricus_), 'Quod ego in senatu cum ad
rationem et loci et temporis ex more fecissem, bono civi
convenientissimum credidi eadem illa spatiosius et uberius volumine
amplecti.'
Pliny speaks of his early attempts at poetry:
_Ep._ vii. 4, 2-3, 'Numquam a poetice (altius enim repetam) alienus
fui; quin etiam quattuordecim natus annos Graecam tragoediam scripsi.
Qualem? inquis: nescio: tragoedia vocabatur.'
In Books i.-iii. he appears only as a lover of poetry and a patron of
poets (cf. i. 16; iii. 15). From Book iv. (published A.D. 105) onwards
he appears as a poet. In _Ep._ vii. 4, 6 are thirteen poor hexameter
lines on Cicero; _ibid._ §§ 7-8, 'Transii ad elegos: hos quoque non
minus celeriter explicui: addidi iambos, facilitate corruptus ...
Postremo placuit exemplo multorum unum separatim hendecasyllaborum
volumen absolvere, nec paenitet. Legitur, describitur, cantatur
etiam.' Pliny defends himself for writing light verses in _Ep._ v. 3,
etc. In the later books he refers to another proposed collection of
verses.
_Ep._ viii. 21, 3, 'Liber fuit et opusculis varius et metris.'
Pliny says he did not observe chronological order in publishing his
letters.
_Ep._ i. 1, 1, 'Collegi non servato temporis ordine (neque enim
historiam componebam), sed ut quaeque in manus venerat.'
This, however, is not convincing, as it falls in with
Pliny's wish to give an appearance of negligence to the work, and
besides it may apply only to Book i. Successive publication of the
different Books is shown by many references; so _Ep._ ix. 19,
'Significas legisse te in quadam epistula,' where _Ep._ vi. 10 is
referred to. So also contemporaneous events are always described in
the same Book or in two Books close together; and when a subject is
continued in another letter, the order of the two letters fits in with
chronology. So iii. 4 and iv. 1 deal with the building of a temple at
Tifernum; iii. 20 and iv. 25 with ballot at elections.
The following are the probable dates of publication: Book i. in A.D.
97; Book ii. in A.D. 100; Book iii. in A.D. 101 or 102; Book iv. in
A.D. 105; Book v. in A.D. 106; Book vi. possibly in A.D. 106; Book
vii. in A.D. 107; Book viii. not before A.D. 109; Book ix. probably
about the same time.
The correspondence with Trajan is independent of the nine Books of
letters. The epistles are roughly in chronological order. _Epp._ 1-14
range from 98 to 106 A.D. _Epp._ 15 to the end were probably all
written in Bithynia during Pliny's governorship there. Trajan's reply
is subjoined to most of the letters. The correspondence extant
stretches from September A.D. 111 over January A.D. 113.