420 Anatomy Applied to Medicine and Surgety. 



tion, and the superior and inferior frontal, which 

 form the superior, middle and inferior frontal convolu- 

 tions. Behind the fissure of Rolando is the intraparietal 

 fissure, which passes upwards and is parallel in its lower 

 part to the fissure of Rolando, and then, curving back- 

 wards, is parallel to the longitudinal fissure. The intra- 

 parietal fissure terminates near the parieto-occipital fis- 

 sure, and assists in marking off the ascending parietal 

 convolution, while the portion running parallel to the 

 longitudinal fissure divides the parietal lobe into the supe- 

 rior and the inferior parietal lobules. The latter, i.e., the in- 

 ferior parietal lobule, is divided into two gyri one, the an- 

 terior, is the supra-marginal and surrounds the termina- 

 tion of the fissure of Sylvius, while the other the angular 

 -surrounds the posterior end of the superior temporal fis- 

 sure. The posterior portion of this aspect of the brain is 

 formed by the occipital lobe and is divided, by two 

 fissures, into three convolutions, viz., the superior, the 

 middle and the inferior occipital convolutions. Beneath 

 the fissure of Sylvius is the tempero-sphenoidal lobe which 

 is divided, by means of four fissures, into five convolu- 

 tions. The fissures are the superior, the middle and the 

 inferior, and, on the mesial or under surface of this 

 lobe, the collateral. The convolutions are the superior, 

 middle and inferior on the lateral aspect and the fusiform 

 and lingual on the mesial surface. On the mesial surface of 

 the hemisphere is the calloso-marginal fissure, separating 

 the falciform lobe or gyrus fornicatus which surrounds 

 the corpus callosum, from the mesial surface of the fron- 

 tal lobe. The conjoined upper ends of the ascending 

 frontal and parietal convolutions are termed the paracen- 

 tral lobule. Between the hinder end of the calloso- 

 marginal fissure, which curves up to the margin of the 

 cerebrum, and the parieto-occipital fissure, is situated the 



