STRUCTURE OF THE BRAIN 273 



right or wrong in his hypothesis respecting the relative order 

 of appearance of the temporal and frontal sulci, the fact 

 remains that, before either temporal or frontal sulci appear, 

 the foetal brain of man presents characters which are found 

 only in the lowest group of the Primates (leaving out the 

 Lemurs); and that this is exactly what we should expect 

 ^to be the case, if man has resulted from the gradual modi- 

 fication of the same form as that ,from which the other Pn- 

 mates have sprung. 



