great cords of nerve fibre descend towards the body, which are covered by a transverse mass, known as the bridge, appearing complete as a crossing, and containing transverse fibres from the cerebellum, as well as a series of longitudinal fibres. Immediately underneath the bridge are pillars or masses of nerve, constituting the crowning portion of the spinal system, and formed in eight distinct bodies, the two in front and the two in rear being elongated and known as pyramids, those in the centre being rounded in figure. From the elongated bodies, the nerve fibres pass across to the opposite sides of the body. This gathering is known as the _medulla oblongata._ Just beneath comes the spinal canal, from which at the different joints of the spine are given out a suitable supply of sensory and motor nerves as previously described. Having thus given a general account of the central arrangements of the nerve system of the human body, it is important to state that an order of things closely analogous obtains in other and lower orders of organism, in respect of interior plan, so that if the interior of the brain of the dog were laid open to view it would present a plan of distribution very similar to that now described. To complete the view of the functions of the brain as indicated by recent research, I have next to give a brief account of an extended course of experiments of great delicacy designed to ascertain whether it may be possible to localize certain functions within a definite area of the brain. All are familiar with the fanciful subdivisions of the outer surface of the human skull, under the name of phrenology, represented on moulds of the head, all marked with dividing lines and figures. This pretentious and unscientific assumption of knowledge which no one possessed, has had its time of popularity, aided by a general recognition of comparative superiority in head formation in persons of known ability. Any thing equivalent to an exact partition of the bony covering protecting the brain, has not been favored by scientific observations; but these fanciful maps of the head, which have been sold cheap, and fully certified, may serve as a guide to a general notion of what has been attempted on the surface of the brain itself, after removal of the skull. The illustrative aid, however, consists in nothing more than the suggestion of distinct areas, for there is no analogy between what has been discovered by the observations now to be described, and the "bumps" alleged to be found on the cranium.