508 C. JUDSON HERRICK 



EXPLANATION OF FIGURES 



4. Through the caudal part of the interventricular foramen. At the union of 

 the taenia thalami with the taenia fornicis {taenia thai, elforn.) the velum trans- 

 versum sti etches across between the third ventricle above and the ventriculus 

 medius telencephali below. The fimbria complex of fig. 3 here separates into two 

 parts, one of which enters the stria medullaris, the other passes caudad and ven- 

 trad to enter the commissura pallii anteiior (fig. 5). The basal forebrain bundle 

 is imperfectly separated into lateral and medial foiebrain tracts. 



5. Through the posterior pole and anterior commissure. The lattei contains 

 two distinct components, the ventral one a decussation of the medial forebrain 

 tract (med. f. b. t.) and the dorsal one a decussation of the lateral forebrain tract 

 (lal.f. b. t.). Dorsally ot both of these is tne veiy small commissura pallii anterior 

 or commissuraruppocampi. 



6. Section through the brain of a larva of Amblystoma tigrinum 10 mm. long 

 (about 15 days after feitilization) so oriented as to pass through the region of the 

 velum tiansversum (v) in approximately the horizontal plane, the light side being 

 a little farther vential than tne left. X 104. The transitoiy posterioi chorioidal 

 fold is seen at z and the first rudiment of the plexus lateralis at y. 



