Verbal folklore was the original folklore, the artifacts defined by William Thoms as older, oral cultural traditions of the rural populace. In his 1846 published call for help in documenting antiquities, Thoms was echoing scholars from across the European continent to collect artifacts of verbal lore. By the beginning of the 20th century these collections had grown to include artifacts from around the world and across several centuries. A system to organize and categorize them became necessary. Antti Aarne published a first classification system for folktales in 1910. This was later expanded into the Aarne–Thompson classification system by Stith Thompson and remains the standard classification system for European folktales and other types of oral literature. As the number of classified oral artifacts grew, similarities were noted in items that had been collected from very different geographic regions, ethnic groups and epochs, giving rise to the Historic–Geographic Method, a methodology that dominated folkloristics in the first half of the 20th century.