MAN AND APES. 147 



in this respect is the divergence between the 

 Orang and those lowest of Apes — the Marmo- 

 sets — in which the cerebrum is smooth and 

 entirely devoid of furrows and convolutions. 

 In the lower sub-order — the Lemuroids — the 

 divergence is much greater still, so much so, 

 indeed, that the Half-apes, as to their brains, 

 have far nearer resemblances to animals alto- 

 gether below the order Primates than to the 

 higher members of that order. 



It must nevertheless be borne in mind, if 

 we would estimate the value of these cerebral 

 characters with perfect fairness, that forms 

 zoologically distant sometimes resemble each 

 other in brain-characters, while closely allied 

 forms strangely differ. Thus, as M. Gratiolet 

 has pointed out, the " bridging convolutions " 

 between the parietal and occipital lobes re- 

 appear in the Spider Monkeys, while two 

 species of Sapajou (Cebus), so closely allied as 

 to have been sometimes treated as one species, 

 differ strangely from each other in this re- 

 spect. 



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