THE AMYGDALA IN AMPHIBIA 251 
The tractus preopticus of R6éthig (11) reaches the vicinity of 
this nucleus and may effect functional connections with it. In 
Amblystoma this is a slender strand of a very few myelinated 
fibers which run longitudinally in the midplane ventrally of the 
preoptic recess for its entire length. Apparently they are accom- 
panied by a larger number of unmyelinated fibers, but these 
have not been clearly demonstrated. The myelinated tract 
Br, L{tl-2- 1-2 
Fig. 30 Section immediately dorsally of the chiasma ridge, showing the 
olfactory projection tract turning: ventrally along its caudal border. 
at its caudal end rises up along the rostral aspect of the chiasma 
ridge and crosses its dorsal surface to disappear at its caudal 
border. In Necturus the fibers take the same course and are 
clearly traced to a region immediately dorsally of the hypothala- 
mic nucleus of the olfactory projection tract. 
Immediately ventrally of the nucleus of the olfactory projec- 
tion tract in the hypothalamus are neurons of much the same 
type, whose dendrites probably make the same functional connec- 
tions as do those of this nucleus, but whose axons appear to be 
