taxa and lexemes, they used the information to discuss the Tzeltal and how they have a nomenclature system incredibly similar to that of Western botany’s division of plants. The data they had obtained studying the Tzeltal and the lexemic system used to name plants was found to conform, with only a few exceptions, to the hypotheses Berlin, Breedlove, and Raven had laid out. Finally, they attempt to show how the principles demonstrated by the research suggest they can be applied to many ethnobiological classification systems since they are general. "While data on some aspects of ethnobotany and ethnozoology, especially the uses of plants and animals, are available from a wide variety of sources, good materials on the classificatory principles underlying folk biological taxonomy and nomenclature in non-Western societies are sadly lacking (1973). Berlin, Breedlove and Raven began to encourage and emphasize the importance in gaining ethnobiological information regarding nomenclature and utilizing the principles they laid out to increase our knowledge of potentially general cognitive categorizing, the people who use these taxonomic systems, and how these systems can influence our view of the environment around us. In a following article published in the American Ethnologist (1976), Berlin attempted to address some criticisms he had encountered regarding the ethnobiological concept of category, hereafter also referred to as rank, by applying some of his previous principles to new information on biological classification of the Aguaruna. Some claim the boundaries to determine ranks are arbitrary or that there is no validity to the rank concept. The conclusion of the report stated, "[…] the vast majority of conceptually recognized plant classes in Aguaruna are easily accommodated into one of the proposed ranks in a natural and straightforward fashion. These data suggest that ranks are neither arbitrary nor a mere typological cataloging device invented for the convenience of the ethnographer. On the contrary, the Aguaruna’s view of the plant world provides additional support for the hypothesis that the concept of rank is fundamental to all systems of folk biological classification" (1976). Ethnobiological Classification (1992) One of Berlin’s most well known contributions to ethnobiology is his 1992 book, Ethnobiological Classification: Principles of Categorization of Plants and Animals in Traditional Societies. In this book, Berlin analyzes the widespread commonalities in classification and naming purposes of the local flora and fauna among traditional, non-literate societies. It helps develop and reaffirm the "universalist" approach to ethnobiology. He explains the "basic