1892.] NATURAL SCIENCES OF PHILADELPHIA. 211 



Garden, as well as in those described by Bischoff/ Muller," 

 Giacomini.^ In the third Chimpanzee, a nearly adult animal dis- 

 sected by the author, the cerebellum was entirely covered by the 

 cerebrum, and such was stated to be the case in the brain of the 

 Chimpanzee described many years ago by Marshall/ Of eight 

 Chimpanzee brains, in six the cerebellum was found uncovered by 

 the cerebrum, in two covered. 



In a previous communication addressed . to the Academy* 

 it was stated that no one anthropoid ape w-as more closely 

 related to Man in the totality of its organization than another 

 and that no anthropoid now known could be regarded as the 

 ancestor of the other anthropoids, still less as the ancestor of 

 Man, each anthropoid agreeing in some respects with related forms 

 and with Man and differing from them in others. A comparison of 

 the brain of the Gorilla with that of the Orang, Chimpanzee and Man 

 confirms the conclusion then arrived at. While the fissures and 

 convolutions are disposed as we have seen in the brain of the Gorilla 

 in the same manner, generally speaking, as in that of Man or of the 

 Chimpanzee or Orang, it is nevertheless a low type of brain, being 

 much less convoluted than the brain of Man or of either of the two 

 other anthropoids. It might be supposed that this was due to the 

 fact of the brain just described being that of a young animal. That 

 such, however, is not the case is shown by the two other brains of 

 the Gorilla not being any more convoluted, though both of them 

 were larger and heavier and from older animals, 



The brain of the Gorilla further differs from that of Man or of the 

 Chimpanzee or Orang in the markedly pointed shape of its frontal 

 lobe, in the absence of the lower portion of the inferior or third 

 frontal convolution, and in its orbital surface being so concave. With 

 reference to this portion of the frontal lobe in the Gorilla it may be 

 incidentally mentioned that the corresponding part in the brain of 

 the Chimpanzee and especially in that of the Orang, presents the 

 cruciform and orbital fissures disposed exactly as in Man, the 

 orbital fissure being readily distinguished from the anterior branches 

 of the Sylvian fissure. Had all these fissures been present in the 

 brain of their Gorilla the interpretation of the orbital fissure 



1 Gehirn des Champanzee, 1871. 



2 Archiv fur Anthropologic, 1887. 



3 Aui della R. Accad. Torino, 1889. 

 * Natural History Review, 1861. 



^Proc. Acad. Nat. Sciences Philad., 1880. 



