1 148 



HUMAN ANATOMY. 



inferior temporal (Fig. 988), all of which correspond in the general direction of 

 their course with the posterior limb of the Sylvian fissure and extend backward 

 and slightly upward. 



The superior temporal sulcus, also called \\\^ parallel sulcus in recognition 

 of the similarity of its course with that of the posterior limb of the Syhian fissure, is 

 the first in the series of longitudinal furrows, the third of which appears not on the 

 outer, but on the inferior aspect of the lobe. It begins near the temporal pole, runs 

 parallel with the posterior limb of the Sylvian fissure and ends by cutting upward 

 into the inferior parietal convolution, whose angular gyrus surrounds the upturned 

 extremity of the sulcus. 



The middle temporal sulcus, the second in the series, lies below the pre- 

 ceding fissure, whose direction in a general way it follows. It is, however, much 

 less certainly marked and in most cases is not a continuous furrow, as is the superior 

 sulcus, but broken by superficial annectant convolutions into a number of separate 

 pieces, the exact sequence of which is often difificult to follow. The upturned end of 

 the middle temporal sulcus cuts into the lower parietal convolution towards the pos- 

 terior limb of the interparietal sulcus (Fig. 988) from which, however, it is separated 

 by the arching postparietal gyrus. 



Fig. 990. 



Rolandic fissure 



0i -^ 



Right cerebral hemisphere, with opercula displaced to expose island of Reil. 



The superior temporal gyrus intervenes between the posterior limb of the 

 Sylvian fissure and the superior temporal sulcus. Its lower end lies at the temporal 

 pole, whilst above the tract is continuous with the supramarginal and angular gyri 

 of the parietal lobe. 



The middle temporal gyrus, between the upper and middle temporal sulci, 

 is connected with the subjacent convolution by the bridges which interrupt the sec- 

 ond temporal furrow. Above and behind it is continuous with the angular and 

 postparietal convolutions. 



The inferior temporal gyrus occupies the rounded infero-lateral margin of 

 the hemisphere, and appears on both the lateral and the inferior surface of the lobe, 

 being continuous with the occipital lobe behind (Fig. 988). Its upper boundary, 

 formed by the middle temporal sulcus, is indistinct ; its lower and mesial hmit is 

 defined by the inferior temporal sulcus, which separates it from the occipito- 

 temporal gyrus. 



The inferior surface of the temporal lobe is rounded in front, where it rests in 

 the anterior cerebral fossa, but behind is modelled by the upper surface of the ten- 

 torium cerebelli and is, therefore, concave from before backward and slighUy convex 

 from side to side. It presents one fissure, the inferior temporal, and one convolu- 

 tion, the anterior part of the occipito-temporal. 



The inferior temporal sulcus, also called the occipito-temporal, courses longi- 

 tudinally a short distance internal to the infero-lateral border of the hemisphere and 



