The sub-series contains 12 numbered notebooks with Gogerly's translations of various jātaka stories. It seems that the collection is not complete as some of the notebooks are missing. In Theravāda Buddhism, the jātakas (c. 4th century BCE) are a textual division of the Pāli Canon, included in the Khuḍḍaka Nikāya ('Minor Collection') of the Sutta Piṭaka - the second group of the Pāli collection of Buddhist writings. The term mainly refers to the stories of Gautama Buddha's previous lives, in both human and animal form.