An overview of the central nervous system of the elephant through a critical appraisal of the literature published in the XIX and XX centuries

The two species of elephants (Indian: Elephas maximus and African: Loxodont a africana) possess the largest brain among land mammals. Due to its size, the elephant brain is discussed in virtually every paper dealing with the e volution of the central nervous system of mammals and comparative brain siz e. Studies on the social habits of elephants also deal with the skills and the "intelligence" and brain size of these species. Yet most of the descrip tions and conclusions reported in comparative studies rely on second-hand d ata derived from investigations performed several decades before, often dat ing as far back as the XIX century. Furthermore, many of the original paper s actually describing gross and detailed features of the brain of elephants are either no longer available, are written in languages other than Englis h, or are difficult to trace. The present study gives a short description o f the anatomy of the central nervous system of elephants, with special atte ntion to its distinctive features, reports all available literature on the subject, and briefly discusses its origins and rationale. (C) 2001 Elsevier Science Inc.