Henry Gray (18251861). Anatomy of the Human Body. 1918.
either pass over or through the lateral geniculate body to the pulvinar of the thalamus. These end-stations are often called the primary visual centers.
The lateral geniculate body consists of medium-sized pigmented nerve cells arranged in several layers by the penetrating fibers of the optic tract. Their axons pass upward beneath the longer fibers of the optic tract, the tænia semicircularis, the caudate nucleus and the posterior horn of the lateral ventricle where they join the optic radiation of Gratiolet. They pass backward and medially to terminate in the visuo-sensory cortex in the immediate neighborhood of the calcarine fissure of the occipital lobe. This center is connected with the one in the opposite side by commissural fibers which course in the optic radiation and the splenium of the corpus callosum. Association fibers connect it with other regions of the cortex of the same side.
FIG. 763 Scheme showing central connections of the optic nerves and optic tracts. (See enlarged image)
The region of the pulvinar in which optic tract fibers terminate resembles in structure the lateral geniculate body. Its axons also have a similar course though in a somewhat more dorsal plane.
The superior colliculus receives fibers from the optic tract through the superior brachium. Some enter by the superficial white layer (stratum zonale), others appear to dip down into the gray cap (stratum cinereum) while others probably