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THE VOYAGE OF H.M.S. CHALLENGEE. 



fact that the convolutions of the brain in the Apes assume from the first their own 

 method of arrangement, and not necessarily that of the orders of Mammals with con- 

 voluted brains which are lower in the series. Beyond therefore a certain general 

 correspondence in the arrangement of those fundamental parts of the cortex which serve 

 a similar purpose in these various orders, one does not find it possible to determine the 

 presence of convolutions arranged in a precisely corresponding manner in the brains of 

 the Carnivora and Pinnipedia on the one hand, and of Man and Apes on the other. In 

 each of these orders the developmental process which gives rise to the disposition of 

 the fissures and convolutions is regulated by the vital and mechanical necessities of 

 the animals constituting the order, as well as by the conditions of hereditary descent. 

 Subject to the qualifications and reservations which have been just expressed, and with 

 the proviso that the homologies of the cortical areas of the cerebrum are in many instances 

 histological and physiological rather than morphological, the following summary of the 

 corresponding fissures and convolutions in the Dog and the Monkey has been drawn up 

 in a tabular form : — 



Table XIV. 



