Anthropologists earlier believed the tree shrew (Tupaia belangeri) to be a close relative of primates and classified the species in the prosimian suborder. Although that classification has now been questioned, the tree shrew undoubtedly represents a pivotal chapter in the natural history of the evolution of the brain. With its cone dominated retina, this animal is capable of carrying out color discrimination under isoluminant conditions (i.e. where hue alone is the cue). Unlike primates, it is capable of doing so even after ablation of the primary visual cortex. This book purports to be an...