OLFACTORY CENTERS IN TELEOSTS 215 
part of the hypostriatum (nucleus teniae) to the habenulae; 
Kappers and Goldstein make similar observatiqns. Johnston, 
however (98, 01, 702) in Acipenser and Petromyzon finds that 
the larger proportion of the fibers ascending to the habenulae arise 
from the nucleus preopticus, called by him the nucleus thaeniae 
(98, ’01, 702) and nucleus praeopticus (’06). Some fibers in Aci- 
penser are traced from the nucleus postolfactorius ventralis and 
nucleus postolfactorius lateralis, corresponding largely to the 
corpus precommissurale and the area olfactoria lateralis, respec- 
tively. It will thus be noted, as Johnston himself pointed out, 
that the tractus olfacto-habenularis of Acipenser and Petromyzon 
is not the equivalent of that in teleosts, selachians, amphibians, 
reptiles and mammals. The conditions as observed in the carp 
explain this discrepancy, as in this form the tractus olfacto- 
habenularis is equivalent to both the tractus olfacto-habenularis 
of Edinger, etc., and of Johnston (figs. 140, 141, 142). 
The tractus olfacto-habenularis of Catois, Edinger, Kappers, 
etc., the taenia thalami of Goldstein, appears conspicuously as a 
small, heavily medullated bundle, arising from the nucleus 
teniae, lateral to the fissura endorhinalis, at the level of the caudal 
margin of the anterior commissure. ‘This is here termed the trac- 
tus teniae (fig. 55) and corresponds morphologically to the tractus 
cortico-habenularis lateralis of C. Judson Herrick in the Amphi- 
bia (10). 
It extends iatero-caudad, dorsal to the bundles of the basal 
forebrain bundle (figs. 61, 68), where it receives a few unmedul- 
lated fibers from the nucleus intermedius, the tractus intermedio- 
habenularis, pars anterior (figs. 140, 141, 142), possibly homologous 
to the tr. septo-habenularis of Herrick. Slightly caudal to this 
point the tract receives a small number of unmedullated fibers 
from the nucleus entopeduncularis, extending dorsad from the 
praethalamus. This is termed the tractus entopedunculo-haben- 
ularis (fig. 72), and is probably the morphological equivalent 
of the lateral praethalamic portion of the taenia thalami of 
amphibians and reptiles. A large part of these fibers may be 
descending, corresponding to the tr. habenulo-thalamicus of Her- ° 
rick (710). Quite a number of fine unmedullated fibers arise 
