The topography of the nuclei of the diencephalon of the cat

It has been repeatedly pointed out that a detailed aiid comprehensive knowledge of the anatomy of any structure in the animal body is a necessary prerequisite for experimentation on that structure. This general dictum has its owii special application to the central nervous system of mammals-a complex of structures a t once discrete aiid united-whose very complexity has led to frequent differences among anatomists as to the nature, identity, and relatioiisliips of many of i ts more minute and detailed portions. The mammalian dieiicephalon has in the past fifty years been the subject of a long series of anatomical investigations by a number of workers. The thalamus readily yields itself to subdivision into a considerable number of pel1 groups or nuclei, and a review of the literature reveals an amazing variance in the manner in which such subdivisions have been made as well as in the nomenclature applied to these regions. The more obvious divisions of the human thalamus were the first to receive attention, aiicl investigation of the diencephalon of lower mammals receired its first real impetus with the work of Kiss1 in 1889. This work, based on the c:-toarchitectural method, was followed by that of ron Xonakow, who, in 1895, published an excellent account of the thalamus of the cat and dog in which the topographical relationships of the mclei were studied by both fiberand cell-staining methods. TJater. Vogt ( '09) studied the myelo-architecture of the diencephaloii of Cercopithecus, introducing a different terminology. The