It is now more than fifty years since Sir Wilfrid Le Gros Clark (1932a) published his Arris and Gale lectures on the structure and connections of the thalamus. This authoritative overview came at a time when thalamic studies were passing from a descriptive to an experimental phase and, in his review, Le Gros Clark was able to cover virtually every aspect of the organization and development and much of the comparative anatomy of the thalamus then known...