368 ELIZABETH CAROLINE CROSBY 
tic portion of stria terminalis does not cross in the anterior com- 
missure but passes caudad of it and distributes to the preoptic 
region of the same side. 
Alveus 
A large number of the alveus fibers arise as axones of the 
double pyramid and small projection cells of the hippocampus 
and run dorsalward then lateralward and then ventro-lateral- 
ward around the outer border of the ventricle to the pyriform 
lobe (figs. 15 to 21). They distribute during their course to the - 
general cortex, the cortex of the pyriform lobe and at least to 
the anterior end of the nucleus of the lateral olfactory tract 
(the part which is a derivative of Johnston’s small celled portion 
of the pyriform lobe). From the pyriform lobe and quite 
possible from these other regions, axones enter the alveus. 
Probably they distribute to the general pallium and hippocam- 
pal cortex. 
A small number of alveus fibers at the anterior end of the fore- 
brain swing outward between the hippocampus and the primor- 
dial neopallium and distribute along the outer surface of the lat- 
ter. These association fibers between the two cortical areas have 
been very significant in determining the evolution of the prim- 
itive neopallium. 
Fimbria 
This is a term applied to the fibers which border the hippo- 
campal cortex along its ventro-medial boundary (figs. 18 to 21). 
Behind the foramen of Monro these fibers also border the place 
of attachment of the choroid plexus. In the alligator fibers to 
the fornix, to the tractus cortico-habenularis medialis, and asso- 
ciation fibers between the cortex of the pyriform lobe and the 
hippocampus are found in the fimbria. 
Fibrae tangentiales 
These are short association fibers which tie up the medial and the 
dorso-medial portions of the hippocampus (figs. 15 to 21). They 
