We shall not, then, look for poetic quotations in the "Variation." If Virgil is cited, it will be only in connection with the choice of seed corn; and if Homer is mentioned, it will be only because there is no mention of Gallus bankiva either in the "Iliad" or in the "Odyssey." Nor shall we look for poetic excerpts in the "Origin," that wonder of compressed argumentation. But we may fairly turn to the "Naturalist's Voyage," and to the "Expression of the Emotions," and to the "Descent of Man." And if we do, our search will be rewarded.
When, for instance, Darwin is describing in the "Voyage" the feasting of the Indian troops at Bahia Blanca, he not only gives a description which is itself reminiscent of Virgil, but he quotes, in the most natural manner possible, the very words—
Cervicem inflexam posuit, jacuitque per antrum
Immensus, saniem eructans, ac frusta cruenta
Per somnum commixta mero—
in which Virgil in the third book of the "Æneid" describes the gorging of Polyphemus. And when he is surveying the desert behind Port Desire, on the Patagonian coast, he says:
The wilderness has a mysterious tongue,
Which teaches awful doubt.
It is only fair to say that the passage from Virgil occurs in the first draught of the "Voyage," which appeared in 1839 (when Darwin was thirty) as part of Fitz-Roy's work. But then it is also fair to say that the passage from Shelley's "Mont Blanc" occurs for the first time in the edition of 1845.
The "Descent of Man" was published in 1871, when its author was sixty-two. In it he quotes from Tennyson's "Idylls of the King" (1859) the words of Guinevere—
The sins that made the past so pleasant to us—
and, in the second edition (1874), Hookham Frere's rhymed version (1872) of Theognis, Fragment X. The quotation from the Greek poet Xenarchus—"Happy the Cicadas live, since they all have voiceless wives"—bears witness, perhaps, rather to Darwin's sense of humor than to his love of poetry.