134 



ANATOMY OF VERTEBRATES. 



extend forward from the orbital one, I call ' midorbital,' ib. 16' ; 

 that to the inner side is the entorbital, 16"; that to the outer 

 120 side, the ectorbital, 16'"; a 



transverse fissure anterior to 

 these is the antorbital one, 16 X . 

 The ecto- and ento-rhinal fis- 

 sures, 2, 3, distinct posteriorly, 

 run into each other where they 

 form the groove lodging the 

 slender e crus rhinencephali ' of 

 the human brain. The cerebral 

 folds thus marked out are the 

 entorhinal, c (which is the un- 

 der surface of the subfalcial, 

 fig. 118, f), the ectorhinal, d, 

 which, in Ly- and Liss-ence- 

 phala, Ungulata, and most Car- 

 nivora, 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"' ', antorbital, o*. 

 The postorbital tract passes 

 backward into 'Reil's Island.' 

 The ectorbital, o'" ', merges into 

 the ectofrontal, n x , fig. 119, of 

 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 ' Q plis de passage,' lix"). 



On the falcial surface of the frontal lobe the most constant 

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

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

 I falcial,' fig. 118, 15 ; the parallel one below is the s subfalcial,' 15'. 

 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 restino- on 

 the tentorium. 



1 lxxh" and lxxiii". 



trader surface of hemisphere, human cerebrum. 



