376 ELIZABETH CAROLINE CROSBY 
It is with considerable hesitation that the writer has under- 
taken the analysis of the anatomical data given on the preced- 
ing pages. Insufficient time and knowledge and the lack of 
experience have been very clearly realized and the following state- 
ments are offered merely as suggestions or as possible interpre- 
tations of some of the changes occurring and the factors opera- 
ting during forebrain evolution. 
Following the type of interpretation of Edinger, Herrick, Kap- 
pers, and Johnston, centers of the alligator hemisphere may be 
classified under two general heads which may be subdivided as 
follows: 
1. Centers dominated by olfactory impulses 
A. Basal centers 
1. Medial olfactory area 
Nucleus olfactorius anterior (in part) 
Nuclei of the septum (in part), or parolfactory nuclei 
2. Lateral olfactory area 
Pyriform lobe complex (in part) 
Amygdaloid complex (in part) 
3. Intermediate olfactory area 
Tuberculum olfactorium 
Nucleus olfactorius anterior (in part) 
Nucleus of the diagonal band 
4. Correlation centers between telencephalic and diencephalic regions 
Tuberculum olfactorium (in part) 
Parolfactory nuclei (in part) 
Nucleus commissuralis hippocampi 
Bed nucleus of the anterior commissure 
Nucleus preopticus 
Interstitial nucleus of Cajal 
Amygdaloid complex (in part) 
B. Cortical centers (archipallium of Edinger) 
1. Hippocampal formation 
Small celled non-laminated part of hippocampus (the primor- 
dium hippocampi of Johnston, ’13 and ’15) 
Dorso-medial cortex (primordial gyrus dentatus, Elliot Smith, 
°96, Meyer, 792, Levi, ’04) 
Dorsal cortex (hippocampal cortex, subiculum of Johnston ’13) 
2. Lateral cortex (pyriform lobe) 
3. General cortex (to some slight degree) 
11. Centers dominated by ascending somatic impulses from the thalamus 
C. Basal centers 
1. Dorso-lateral area 
2. Intermedio-lateral area 
3. Ventro-lateral areas (comparable to corpus striatum of Johnston ’15) 
