26 
3) The hippocampus is much flatter and generally simpler. The 
curve of the hippocampus is greatly reduced. 
4) The positions of the cingulum (cing) and the “longitudinal asso- 
ciation fibres” (2) are shifted in accordance with the altered po- 
sition of the subiculum (swb). 
Fig. 2. 
The distinctively Eutherian type (Fig. 3). 
Found in the vast majority of mammals. But like all vestigial 
structures the indusium varies greatly even in individuals of the same 
order and species. It is especially well developed in the brains of 
the ox and sheep, but its size does not vary directly with the im- 
portance of the sense of smell as JASTROWITZ, VALENTIN and others 
have stated. 
Fig. 3. 
The transition from the second type is easily followed. The spe- 
cial features are to following: 
1) The hippocampal factor in the “commissura dorsalis” 
(C. S) is practically, if not absolutely, non existent in the region 
which the scheme represents. The “commissura dorsalis” 
is now the corpus callosum. 
