[[NB. bold numbers below indicate the relevant chapter or chapter and sentence in the Agricola.]]
As already remarked, the two authors who exerted the greatest influence upon the style and vocabulary of Tacitus are Vergil and Sallust; but, indisputable as this is, we must guard against the temptation of regarding all striking parallelisms as so many direct reminiscences. Many Vergilian phrases, and the same is true of Sallust, had, by the time Tacitus composed the Agricola, become common property. In fact, if the prose of the post-Augustan age be distinguished from the Ciceronian period by one feature more than another, it is its profound indebtedness to the language of the poets, Livy, whose phraseology is also under heavy obligations to Vergil, standing at the threshold of this movement. In the following some of the more noteworthy of the stylistic parallelisms between Tacitus and earlier writers, pointed out in the Notes, are briefly summarized:
a. Vergil: 3 subit; 5 non alias; 5 castrorum rudimenta; 6, 12, 43 medius, patiens, securus, with genitive; 8 peritus, with infinitive; 10 use of ingens; 12 saxis avelli; 13 monstratus fatis (Aen. VI.869); 14 rebellibus; (xxxvi) 15 exceptum (Aen. IX.271); 18 praesumere as a passive (Aen. XI.18); 25 hinc ... hinc (Aen. I.500); 29 adfluebat; 29 cruda ac viridis senectus; 37 aliquando etiam victis ira virtusque; 39 curis exercitus (Aen. V.779); 42 famam fatumque; 45 honori.
b. Horace: 15 aeque ... aeque; 18 tarda (active); 31 numerus.
c. Ovid: 15 ex facili; 21 in bella faciles; 31 sumite animum.
d. Lucan, for whom Tacitus appears to have had a special fondness, has left his traces, perhaps, in 25.1 = 4.196 ff.; 38 incerta fugae vestigia; 38 spargi bellum.
e. Sallust: see 1-3 and Cat. 3f., Jug. 3f.; 4ff. and Cat. 5; Jug. 3f.; 5 and Jug. 5; 10-17 and Jug. 17-19; the speeches in 31-33 and Cat. 51f.; Mithridates' letter (fragm. 4.17). Phraseological parallelisms would doubtless have been found in still greater abundance, if Sallust's Histories had been preserved entire. See 5.2, 26.2 = Jug. 114.2; 11.1 = Jug. 17.7; 12.5 = Hist. fragm. 1.9(10); 18.2 = Cat. 59.1; 18.3 = Cat. 53.1, Jug. 92.1; 18.2 = Jug. 84.3, 100.4; 20.2 = Jug. 88.2; 26.1 = Cat. 45.1; 27.1 = Jug. 53.8; 30.1 = Cat. 58.18; 32.1 = Hist. fragm. 4.61(19).7; 33.4 = Cat. 68.9f., Jug. 114.2; 36.3 = Hist. fragm. 1.104(96); 37.2 = Jug. 101.11.
f. Livy: Tacitus does not seem to have been under great or conscious obligations to Livy, for of the parallelisms recorded in the Notes many are probably due to their common indebtedness to Vergil. The speeches of Hannibal and Scipio at Ticinum in particular and the battle descriptions do indeed exhibit numerous structural and stylistic resemblances to passages in the Agricola; but here, too, it is doubtful to what extent they merely represent stereotyped commonplaces of the rhetorical vernacular.
g. Curtius: The numerous coincidences between ch. 30-38 and Curtius are, again, mainly confined to his speeches, and are, therefore, with greater likelihood explained on the assumption of similar rhetorical models than by direct indebtedness on the part of Tacitus. See esp. Curt. 4.3.9ff. and 33; 3.8.10 and 34.2; 7.8.19 and 32.1.
h. The remarkable parallelisms with Isocrates' Euagoras and Xenophon's Agesilaus are probably not actual reminiscences, for (xxxvii) these two treatises are frequently cited as stock models for biographical encomia by ancient rhetoricians. See 44.3 and Isoc. Euag. 28; 46 and ibid. 1, 75; 22.4 and Xen. Ages. 11.10; 45.3 and ibid. 5.3; 46.3 and ibid. 11.14. See Introd., p. x.
i. A number of figurative expressions not hitherto mentioned also contribute their share in giving to this treatise its noteworthy poetical and rhetorical coloring, many of the metaphors and personifications being of a very bold character, generally coined by the author, or at least not found elsewhere, or extremely rare: 1 virtus vicit ac supergressa est; 9 comitante opinione; 10 montibus inseri velut in suo (sc. mari); 11 segnitia cum otio intravit; 14 terga occasioni patefecit; 16 vitiis blandientibus; 18 transvecta aestas; 20 famam paci circumdedit; 22 intrepida hiems; 30 recessus ... sinus famae ... defendit; 30 a contactu, etc.; 31 Britannia emit ... pascit; 31 Caledonia ... viros seposuerit; 33 virtute et auspiciis imperii Romani; 33 fama ... rumore ... tenemus; 33 vota virtusque in aperto; 34 furto noctis; 34 imponite ... annis magnum diem; 36 gladii ... tolerabant; 38 dies faciem victoriae latius aperuit; 38 praecesserat terror; 40 otium ... hausit; 41 in gloriam ipsam praeceps agebatur; 44 per spiramenta temporum ... uno ictu rem publicam exhausit; 45 suspiria nostra subscriberentur; 45 innocentia ... donares.
j. Finally, a list of the few ἅπαξ εἰρημένα in this treatise may be given, i.e. words either first found in Tacitus or used by him in new meanings: 3 dissociabilis in the sense of incompatible; 5 anxius; 10 percoluere = exornavere; 10 obtenditur; 12 natura, good quality; 19 devortia; 19 conmodare = adhibere; 20 inlacessita; 35 cornibus adfunderentur; 35 covinnarius; 42 inrevocabilis = implacabilis; 45 comploratus.
 See Dial. 20.5 Exigitur enim iam ab oratore etiam poeticus decor.