444 PROFESSOR G. ELLIOT SMITH. 



lobe." Upon supposed morphological grounds Broca separated 

 the olfactory bulb and its peduncle, the locus perforatus 

 anticus, the uncinate gyrus, and the callosal gyrus as a great 

 cortical ring completely surrounding the hilum of the hemi- 

 sphere. He supposed these regions to be still further united 

 physiologically as all appertaining to the sense of smell. With 

 various modifications proposed by different anatomists, the main 

 idea of this " limbic " or " falciform lobe," as Schwalbe calls 

 it, has met with a very wide acceptance. As at present most 

 usually interpreted it includes the gyrus fornicatus, the gyrus 

 uncinatus, hippocampus and septum lucidurn, in addition to the 

 basal structures already enumerated. 



But to such a subdivision there is an unsurmountable objec- 

 tion. Even granting, for the sake of argument, that the gyrus 

 fornicatus and gyrus uncinatus were exclusively olfactory in 

 function — which is very far from the truth — this would not 

 justify VIS in separating this strip of the neopallium^ from the 

 whole of the rest of the same histological formation, in defiance 

 of the most obvious morphological principles. 



Turner adopted the ideas of Broca only so far as to include 

 in his " rhinencephalon " those parts of the hemisphere which 

 he regarded as indubitable connections of the olfactory appa- 

 ratus ; and to institute a contrast to which Turner gave a 

 concrete form in the shape of complementary terms, between 

 the olfactory and the non-olfactory parts of the hemisphere. 



The idea of subdividing the mesial surface of the hemisphere 

 into a series of concentric areas seems to exert some strange fasci- 

 nation over the minds of morphologists within recent years, thanks 

 very largely to the writings of Zuckerkandl. What exactly is 

 gained when the mesial surface has been thus arbitrarily split up 

 into " Randwindungen " is not very evident, unless it be the fact 

 that Broca's ideas of a " limbic lobe " and Schmidt's conception 

 of " Bogenwindungen " both find expression in this exercise of 

 the imagination, generally so futile and meaningless. 



The chief fallacy in Broca's great morphological excursus I 



1 For the vvliole of the gyrus fornicatus and the greater part of the gyrus unci- 

 natus of Human Anatomy are neopallium. Exclude this strip of neoi)allium from 

 Schwalbe's "falciform lobe," and we have the " rhinencepJucloa" or " p((rs 

 limhica hemlspJucrii '' of these notes. 



fc) 



