517 



the terras employed in describing the brain in lowlier vertebrata have 

 been applied originally to the mammalian brain. Thus it happened 

 that BuRCKHARDT sought for and, as he imagined, found the "Ammons- 

 born" (i. e. hippocampus) in a situation topographically analogous to 

 that in which it occurs in the Eutheria i. e. at the ventral edge of 

 hemisphere, instead of looking for it at the dorso-mesial edge, where 

 it is actually found (Fig. 1). 



This preliminary error — which was a natural mistake to make 

 in 1892 — led to an utterly false interpretation of the homologies 



Fig. 3. A photograph of a similar section through an immature brain. 



of all the other parts of the hemisphere. The paraterminal body 

 (Fig. 1) became for Burckhardt (see his Taf. Ill, Figures 21, 22 

 and 23) the corpus striatum, although it is placed in the mesial and 

 not in the ventro-lateral walls of the hemisphere. Like so many of 

 his contemporaries he confused the terms "Ammonshorn" and "Lobus 

 hippocampi", the one with the other, although the former is the 

 hippocampus and the latter the pyriform lobe — two entirely distinct 

 pallial areas, one the mesial and the other the lateral edge of the 

 pallium (vide infra). 



Even at the present day it is a very common mistake to confuse 

 the swollen end of the peduuculus olfactorius attached to the cerebral 



