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“I 
OLFACTORY CENTERS IN TELEOSTS 
4. THE FIBER TRACTS 
a. Crural tracts 
The olfactory neurones of the first order from the olfactory 
mucous membrane to the olfactory bulbs and their connections 
at that point have already been described. The connections 
between the bulbs and hemispheres will next be considered. It 
has long been known that the fibers of the olfactory tracts pass 
between the bulbs and olfactory lobes in two bundles; Bellonci 
was the first to divide the tracts into a medial and a lateral. 
C. L. Herrick in 1891 brings out clearly the morphological rela- 
tions of these two tracts, which he ealls the radix lateralis and the 
radix mesalis. He points out that the radix lateralis passes 
directly from the bulbs to the caudo-lateral part of each basal 
lobe, which he terms hippocampus, and that the radix mesalis 
decussates in the anterior commissure. Edinger (’96) figures a 
horizontal projection of the basal lobes of the carp, in which he 
traces the lateral tract, called by him the tractus bulbocorticalis, 
into a region termed the area olfactoria, while the median olfac- 
tory bundle, or tractus bulbo-epistriaticus, ends partly in the epi- 
striatum of the same side, and partly decussates in the anterior 
commissure. Catois (’01) identifies the same two bundles as 
‘Le faisceau externe’ and ‘Le faisceau interne.’ Catois is the 
first to point out that the medial tract consists of both centri- 
petal and centrifugal fibers. He agrees with Edinger that it is 
partly crossed and partly uncrossed. Bela Haller likewise identi- 
fies the two tracts. Goldstein (’05) has worked out the relations 
of the bundles in more detail than his predecessors, and finds that 
the lateral tract, ‘laterale Riechstrahlung,’ originates in the lobus 
olfactorius anterior and ends, largely uncrossed, in the lobus 
olfactorius posterior, pars lateralis, while a few fibers decussate 
in the anterior commissure to end in the same area on the opposite 
side. The ‘mediale Riechstrahlung’ is formed, according to 
Goldstein, entirely from centripetal fibers, which run in several 
distinct bundles. The more lateral originates in the lobus olfac- 
torius anterior, and decussates in the anterior commissure to 
