Spurred by the growing interest in folk verbal art throughout Europe, Karel Jaromír Erben planned to write a systematic treatise on Czech folklore and verbal art under the title Obyčeje národa českého (Customs of the Czech Nation). Although the project never came to fruition, Erben used the collected material including fairy tales, songs and customs, for several works with ethnographic subject matter. One of them was a collection of folk songs and rhymes Písně národní v Čechách (Folk Songs of Bohemia), published in three volumes between 1841 and 1845. For its second edition, published as Prostonárodní české písně a říkadla (Czech Folk Songs and Nursery Rhymes, 1860), he added nearly two thousand more items. He also included some children's rhymes, riddles, games, proverbs, and incantations in the collection, which was divided into sections following the stages of the human life, seasons of the year, and various occupations.