It is best examined fresh. If numbers of brains have to be prepared and kept, I have found it a good plan to put them first in a solution of chloride of zinc, just dense enough at first to float them, and to leave them for a fortnight or less. This softens the pia mater, which can then be removed in large shreds, after which it is enough to place them in quite weak alcohol to preserve them indefinitely, tough, elastic, and in their natural shape, though bleached to a uniform white color. Before immersion in the chloride all the more superficial adhesions of the parts must be broken through, to bring the fluid into contact with a maximum of surface. If the brain is used fresh, the pia mater had better be removed carefully in most places with the forceps, scalpel, and scissors. Over the grooves between the cerebellum and hemispheres, and between the cerebellum and medulla oblongata, thin cobwebby moist transparent vestiges of the _arachnoid_ membrane will be found. The subdivisions may now be examined in due order. For the convolutions, blood-vessels, and nerves the more special books must be consulted. First, looked at from above, with the deep _longitudinal fissure_ between them, the hemispheres are seen partly overlapping the intricately wrinkled _cerebellum_, which juts out behind, and covers in turn almost all the medulla oblongata. Drawing the hemispheres apart, the brilliant white _corpus callosum_ is revealed, some half an inch below their surface. There is no median partition in the cerebellum, but a median elevation instead. Looking at the brain from below, one still sees the longitudinal fissure in the median line in front, and on either side of it the _olfactory lobes_, much larger than in man; the _optic tracts_ and _commissure_ or _'chiasma'_; the _infundibulum_ cut through just behind them; and behind that the single _corpus albicans_ or _mamillare_, whose function is unknown and which is double in man. Next the _crura_ appear, converging upon the pons as if carrying fibres back from either side. The _pons_ itself succeeds, much less prominent than in man; and finally behind it comes the medulla oblongata, broad and flat and relatively large. The pons looks like a sort of collar uniting the two halves of the cerebellum, and surrounding the medulla, whose fibres by the time they have emerged anteriorly from beneath the collar have divided into the two crura. The inner relations are, however, somewhat less simple than what this description may suggest.