410 J. J. KEEGAN 



well represented in both hemispheres. Appleton ('10) has classi- 

 fied this as a fetal tendency. The narrow antero-posterior 

 width of the gyrus arcuatus posterior is a noticeable feature and 

 might be indicative of an unusual growth in the superior parietal 

 area. 



The sulcus parietalis superior is poorly represented, perhaps 

 due to its partial incorporation in surrounding sulci. 



The lobulus parietalis inferior gives evidence of a prominent 

 growth. This is more noticeable in the left hemisphere where 

 the prominent sulcus interparietalis extends into the anterior 

 region as an accessory fissure. The s. angularis, which to some 

 extent is an index to the growth of the inferior part of this lobule, 

 is not independent from the s. temporalis superior as found in 

 the majority of Negro brains. It appears as the sharply upturned 

 extremity of this fissure, more anterior in the left hemisphere. 



The sulcus temporalis superior of the right hemisphere was 

 injured by the tumor growth. The absence of the anterior trans- 

 verse element may be associated with an increased growth of the 

 acoustic area of the superior temporal gyrus. This was further 

 evidenced by very prominent transverse temporal gyri of Heschl 

 and the extension to the lateral surface of the fissure separating 

 the two larger of these gyri. 



The sulcus temporalis medius and the sulcus temporalis 

 inferior have never been interpreted well enough to permit mor- 

 phological comparison. The ascending ramus of the former, 

 sulcus occipitalis anterior of some authors, is typical in the right 

 hemisphere of an arcuate communication with the s. occipitalis 

 inferior, classified by Appleton ('10) as a simian character. 



The fissura rhinalis is present in both hemispheres as a shallow 

 groove connecting the Sylvian fossa with the s. collateralis. 

 The interpretation of these two fissures, applied as in the Negro 

 brain, indicates an earlier or less developed condition in the 

 right hemisphere but in neither is the simian or fetal type ap- 

 proached, regardless of the greater depth than u.sual. 



The sulcus collateralis is superficially continuous to the occipi- 

 tal region in both hemispheres. The posterior portion lies con- 

 siderably more lateral in the right, which, as a limiting sulcus 

 for the area peristriata, would indicate a greater extent of this 



