passer: the occurrence of this word and its diminutive as pet names in the works of Plautus shows that even much earlier than this the Romans were accustomed to make pets of sparrows: cf. Pl. Cas. 1.50 “meus pullus passer” ; Pl. As. 3.3.74 “dic igitur me tuum passerculum.” Other names of birds are used in the same way (cf. l.c.), and other birds are mentioned as pets; cf. Catul. 68.125 (columbas); Pl. Capt. 1002 (monedula, anas, coturnix); Ov. Am. 2.6.1 “psittacus … occidit” ; Stat. Silv. 11.4. I “psittace … domini facunda voluptas” ; Mart. 1.7.1 “Stellae delicium mei columba” (cf. Mart. 7.14. 5); Mart. 14.73 (psittacus); Mart. 14.74 (corvus); Mart. 14.75 (luscinia); Mart. 14.76 (pica), etc. The sparrow was sacred to Aphrodite, according to Sappho, and so an especially fitting pet for Lesbia.
deliciae: of a living object of endearment; cf. Catul. 6.1; 32.2; and the repetition of this verse, Catul. 3.4. Elsewhere in Catullus deliciae is used of inanimate objects (Catul. 69.4） and of acts of endearment (Catul. 45.24; Catul. 68.26; Catul. 74.2).
 desiderio: first of a passionate desire for something once enjoyed (cf. Catul. 96.3; Hor. Carm. 1.24.1 “quis desiderio sit pudor” ), and then of the object of desire (cf. Hor. Carm. 1.14.18 “[navis] nunc desiderium curaque non levis” ) . From this point the transition is easy to a mere pet name, as here; cf. Cic. Fam 14.2.2 “Hem, mea lux, meum desiderium” ; Petr. 139 “tu, desiderium meum. ”
 carum: here an almost colorless word, somewhat as the Homeric φίλον often is. It modifies nescio quid, the object of iocari, which takes this less marked sort of a cognate accusative; cf. Cic. Fam. 9.14.4 “haec enim iocatus sum” ; Hor. S. 1.5.62 “in faciem permulta iocatus.” The infinitive-phrase is then the subject of libet.
 et solaciolum: the general sense is, ‘My love in playing with her sparrow finds amusement,—yes, and comfort, too, for by this means she stills the torturing flames of her passion.’ The play with the sparrow is indulged in both for its own sake and as a distraction from fiercer passion. Vv. 7 and 8 contain, therefore, a sort of rhetorical after-thought, and may properly be considered parenthetical; and while a noun could not stand directly as the subject of libet, solaciolum may yet, by virtue of the remote character of its modification in the afterthought, be allowed as an appositive to the subject. See Crit. App.
 ut tum: the constant confusion of t and c in the MSS. makes entirely probable the emendation of cum of V to tum. The ut-clause carries on with specification the sol. sui dol. of v. 7, the repetition being made less tautological by the emphasis laid upon gravis; cf. Catul. 10.7ff., and Catul. 96.3, where there are similar explications of preceding phrases.
 ipsa: this demonstrative is sometimes used with even a more remote reference, so that it is equivalent to some such word as dominus (cf. Catul. 64.43n.), but the reference to puellae v. 1 is here more immediate.
 possem: optative of ungratified wish.
 tristis animi curas: of the painful passion of love, as v. 7 doloris; cf. Catul. 64.72, Catul. 64.95; Catul. 68.18; Hor. Epod. 2.37 “quas amor curas habet.” With animi modifying curas cf. Catul. 64.372 “animi amores” ; Catul. 68.26 “delicias animi” ; Catul. 102.2 “fides animi.”Some critics have judged that vv. 1-10 form a complete whole, or that, at any rate, vv. 11-13 are the conclusion of some other poem and not of this (cf. Crit. App.). But there seems to be no good reason to doubt that the poem is not concluded with v. 10, while a study of Catul. 65.1ff. shows how naturally such a picture as that of vv. 11-13 may conclude a poem of warm emotion. Yet the change of mood from possem (v. 9) to est (v. 11) makes it probable that a lacuna exists here, though perhaps of only a single verse, containing in the form of an infinitive-phrase some repetition of the thought in tecum ludere sicut ipsa.
 quam: etc., the comparison is, of course, a limited one, extending only to the delight Atalanta took in securing the apple.
 puellae pernici: for the familiar story of the victory of Hippomenes (or Milanion) over the beautiful Atalanta in the foot-race by the help of Aphrodite's golden apples, cf. Apollod. 3.9. 2; Ov. Met. 10.560ff.; Hygin. Fab. 185. Catullus means us to understand, as does Ovid (Ov. Met. 10.610 ff.), that not only was the beautiful apple attractive to Atalanta, but she herself was not altogether unwilling to be beaten.
 zonam: for similar reference see Catul. 61.52; Catul. 67.28; and cf. Paul. Fest. p. 63 “cingulo nova nupia praecingebatur, quod vir in lecto solvebat, factum ex lana ovis.” The figure is as old as Homer; cf. Hom. Od. 11.245.