At the beginning of the thirteenth adhyāya of the Aitareya Brāhmaṇa occurs a story which narrates how the metre Gāyatrī brought from heaven soma for gods and sages. Having gone to heaven, she frightened the guardians of soma, picked it up in her feet and mouth, and started to return. At this point, one of the guardians of soma, Kṛśānu by name, shot an arrow at her which cut off the nail of her left foot. From that nail arose a porcupine (śalyakaḥ), and the fat (vaśam) that flowed became a barren cow (vaśā). The Brāhmaṇa text (as read by Keith, following Aufrecht) then goes on to say: atha yaḥ śalyo yad anīkam āsīt sa sarpo nirdaṁśy abhavat sahasaḥ svajo yāni parṇāni te manthāvalā yāni snāvāni te gaṇḍūpadā yat tejanaṃ so 'ndhāhiḥ so sā tatheṣur abhavat. Keith (Ṛgveda Brāhmaṇas (HOS, XXV), Cambridge, Mass., 1920) translates the passage as follows: ‘The socket and the point became a serpent, not biting; from its swiftness (came) the viper; the feathers became flying foxes, the sinews earthworms, the shaft the blind snake. Thus became the arrow’.