178 



JOSEPH DUERSON STOUT 



DESCRIPTION OF THE CAT S BRAIN 



The accompanying diagram (fig. 1) illustrates the principal 

 features of the anterior part of the cat's brain, and, as far as 

 they refer to the present work, they may be described as fol- 

 lows: The approximate measurements of the cerebrum are: 

 antero-posteriorly, 5 cm.; transversely, 4 cm.; and vertically, 3 

 cm. The sulcus cruciatus occupies a prominent position on the 

 anterior portion of the superior surface, extending outwards 

 from the median line about 5 mm. On the mesial surface of the 

 hemisphere, it extends backwards and slightly downwards for 



(b) 



FIG. 1. Appearances of cat's brain from (a) the lateral aspect, (b) the su- 

 perior aspect, and (c) the mesial aspect. C.C., corpus callosum; S.M., supra- 

 marginal gyrus; S.Cr., crucial fissure; F.So., supraorbital fissure; L.O., olfactory 

 lobe; F.Rh., rhinal fissure; F.L., lateral fissure; C.A., compensatory ansate fis- 

 sure; F.Cor., coronal fissure (adapted from Wilder and Gage). 



the same distance. When the posterior bank is lifted backwards, 

 the cortical structure, extending into the sulcus, is seen to have 

 approximately the shape of a quadrant of a circle, the outer 

 boundary curving downwards, backwards, and inwards from the 

 superior surface to the mesial surface of the hemisphere. An 

 artery is invariably found on the surface of the hemisphere at the 

 junction of the margins of the sulcus, but with care the posterior 

 bank of the sulcus may be lifted back, leaving the artery on the 

 anterior bank, with slight injury and little hemorrhage. About 

 7.5 mm. in front of the crucial sulcus is the deep depression, 

 marking the union of the olfactory and frontal lobes. The 

 olfactory lobe is parallel to and extends downwards from the 



