When the late fifteenth-century humanist Domizio Calderini began his project of lecturing and then compiling printed commentaries on such ‘difficult’ authors as Juvenal, Martial, Statius and Propertius, the elder Pliny’s Natural History, with its treasure trove of multifarious information, was one of his main sources. Indeed, the frequency with which the notes on Silius Italicus which are the subject of this paper draw on the Natural History was one of the factors supporting their attribution to Domizio Calderini. The notes stemming from Calderini’s lectures on Silius probably date from 1470-73. In his extant works, in the commentaries on Martial, Juvenal, Statius Silvae and Ovid Ibis, Calderini makes specific references back to his lectures on Silius sixteen times with such phrases as ‘in commentariis Silii recitavimus’ (ad Stat. Silv. 2.2.61) and ‘ut apud Silium exposuimus’ (ad Mart. 1.87.5).