from the front, so as completely to disturb the real relative positions of the cerebrum and cerebellum; and the cerebral arachnoid and pia mater have not been taken away. The internal dissection is almost unintelligible.
Tiedemann's two, more carefully drawn, figures represent an apparently, well preserved, specimen, then, and probably now, in the Hunterian Collection. From its small size, and from the imperfect development of the convolutions, this brain was, most likely, taken from a very young animal; the cerebral membranes have been removed; the vertex is somewhat flattened; the orbital surfaces have lost their characteristic concavity; the middle lobes have sunk asunder; and the cerebellum has, undoubtedly, been a little displaced backwards.
Macartney's two figures were drawn from plaster casts of the brain, taken before the cerebral arachnoid and pia mater were removed—at least this is evident enough in regard to the basal view. In size, these figures exactly correspond with the brain in my possession. Owing, probably, to the unavoidable pressure and disturbance in the casting, there is, in spite of the support afforded by the cerebral arachnoid, even more subsidence of the parts at the base, than appears in Tiedemann's corresponding figure. The orbital surfaces, though tolerably concave, are too wide across their base; the points of the middle lobes have fallen asunder; and the cerebellum has, clearly, slid backwards from the hollow of the cerebrum, into which it would naturally fit: moreover, the convolutions are somewhat conventionally drawn and, in certain parts, imperfectly and inaccurately represented.
In the various figures given by Schroeder van der Kolk and Vrolik, the brain is shown, entirely divested of its membranes; the convolutions are carefully and artistically rendered; but all the above-mentioned results of subsidence of the entire encephalic mass, both laterally and from vertex to base, and the consequent distortion and displacement of its parts, are particularly noticeable; so that, on a question of form and relative position, these now famous representations must come to be regarded as wholly unsafe guides. Barring a certain primness of style, these figures are most carefully executed, and they bear a critical comparison with our photographed views, figs. 2, 4 and 5; but, the very closeness of resemblance between the basal and lateral views and our figs. 2 and 4, shows that all have equally been copied from nearly similarly sunken, or flattened, brains. The width and evenness of the orbital surfaces, the severance of the points of the middle lobes, the dragging back of the cerebellum, and the sinking in of this last-named part between the hemispheres; or, viewed in its effect from above, the sliding of the posterior extremities of the hemispheres, forwards and sideways, over the cerebellum, are all very obvious. One can note, especially, that owing, doubtless, to circumstances connected with the state of the brain, or its mode of preparation, suspension, or support, the unnatural lateral separation of the cerebral hemispheres behind, is greatly exaggerated; as
