134 



ANATOMY OF VERTEBRATES. 



120 



extend forward from the orbital one, I call ( midorbital,' ib. 1 6' ; 



that to the inner side is the entorbital, IG"; that to the outer 



side, the ectorbital, IG'" ; a 

 transverse fissure anterior to 

 these is the antorbital one, u x . 

 The ccto- and ento-rhinal fis- 

 sures, 2, 3, distinct posteriorly, 

 run into each other where they 

 form the groove lodging the 

 slender ' crus rhinencephali ' of 

 the human brain. The cerebral 

 folds thus marked out arc the 

 entorhinal, c (which is the un- 

 der surface of the subfalcial, 

 fig. 118, t') 9 the ectorhinal, d, 

 which, in Ly- and Liss-ence- 

 phala, Unyulata, and most Car- 

 niuora, is continued backward, 

 uninterruptedly, into the basi- 

 rhinal tract, b ; external to d, 

 fig. 120, are the postorbital, o, 

 midorbital, o', entorbital, o", 

 ectorbital, o f " ', antorbital, o x . 

 The postorbital tract passes 

 backward into ' Reil's Island.' 

 The ectorbital, 0"' menyes into 



* * o 



the ectofrontal. rc x , fio*. 119, of 



** * O ? 



which it may be called the un- 

 der surface : attention has been 

 called to the coincidence of loss 

 or defect of speech with lesion in that fold or locality of the 

 brain. 1 The tracts connecting some of the folds of which the 

 homology with those of lower mammals is determinable, are noted, 

 in anthropotomy, as ( annectant gyri ' (' plis de passage,' Lix"). 



On the falcial surface of the frontal lobe the most constant 

 fissures are two that aifect a longitudinal course ; the upper one, 

 which seems to be a continuation of the ( marginal ' fissure, is the 

 * falcial,' fig. 118, 15 ; the parallel one below is the i subfalcial,' is'. 

 ^The posterior lobe of the hemisphere, marked off by the lamb- 

 doidal fissure, 13, has three principal surfaces : one applied to the 

 superoccipital plate, one applied to the falx, and one resting on 

 the tentofium. 



1 LXXH" and LXXUI". 



Under surface of hemisphere, human cerebrum. 



