THE AMYGDALA IN AMPHIBIA 259 
5. Commissural connections. 
6. Correlation tracts to and from the medial wall. 
In the course of differentiation of the cerebral hemisphere each 
of these six factors may be variously subdivided and the com- 
ponent parts related physiologically among themselves and to 
other parts of the brain as required by the mode of life of each 
species. 
com.amg.-~ 
d. amg.hab~ he 
tramghab- 
hab.~ 
Fig. 836 Diagram of the frog brain similar to the last to illustrate additional 
connections of the amygdala. 
8} —— ote 
The urodele hemisphere exhibits no regions in the lateral wall 
behind the olfactory bulb which are related specifically to any of 
these systems. The anuran dorsolateral and _ ventrolateral 
parts of the hemisphere are here incompletely distinguishable 
only by the internal connections of their dominant fiber tracts. 
The entire lateral wall, except perhaps the caudal part of the 
ventrolateral nucleus, receives fibers of the lateral olfactory 
tracts, and hence is to be regarded as lateral olfactory nucleus, 
though these fibers are very unevenly distributed within it. 
Most of the fibers of the lateral olfactory tract enter the compact 
