Dog
Dog
The Human brain
The engraving represents not an actual dissection, but the plan of the fibres as understood by the anatomist. The intricacy of the cerebral structure is so great that it would require a vast number of skilful dissections and engravings to make a correct portrait. Fortunately, this is not necessary for the general reader, who requires only to understand the position of the organs in the head, and the direction of their growth, which is in all cases directly outward from the central region or ventricles, so as to cause a prominence of the cranium—not a “bump,” but a general fulness of contour. Bumps belong to the growth of bone—not that of the brain.
The human brain
If the reader has not fully mastered the intricacy of the brain structure, he will find his difficulties removed by studying two more skilful dissections. The following engraving presents the appearances when we cut through the middle of the brain horizontally and reveal the bottom of the ventricles, in which we see the great ganglion, or optic thalamus and corpus striatum, and the three localities at which the hemispheres are connected by fibres on the median line, called anterior, middle, and posterior commissures. These commissures are of no importance in our study; they assist the corpus callosum in maintaining a close connection between the right and left hemispheres.