238 C. JUDSON HERRICK 
about 15 mm. long, with well-developed fore legs, and the meta- 
morphosis was imminent, Dr. McKibben’s notes stating, “these 
toads would have hopped from the water 2 to 4 days after they 
were killed.” 
In horizontal sections stained with hematoxylin and eosin the 
large vomeronasal nerve can readily be followed from the vom- 
eronasal organ back to its termination in the vomeronasal forma- 
tion, crossing the ventral surface of the main olfactory nerve 
close to its junction with the olfactory bulb in the way described 
by McCotter (’17, p. 67) for adult Rana catesbiana. 
The vomeronasal formation is well differentiated, but is not so 
large or so sharply separated from the olfactory formation of the 
bulb as in the tadpoles of Rana catesbiana of corresponding age 
nor are the neurons of the amygdala so clearly separated from 
those of adjacent areas. In similar sections stained in various 
ways these relations are confirmed, the ventrolateral olfactory 
tract can be followed clearly and the dorsal olfactory projection 
tract obscurely. The nucleus of the latter tract is not well dif- 
ferentiated from the surrounding gray matter in any, of these sec- 
tions of larval forms. 
Our material of larval Anura is not extensive; the observations, 
though fragmentary, are sufficient to indicate that the vomero- 
nasal formation, ventrolateral olfactory tract, and amygdala are 
organized essentially as in the adult. 
Ill. URODELA 
The olfactory nerve of Amblystoma 
From our collection of urodeles I shall select for first considera- 
tion the brain of adult Amblystoma, of which we have abundant 
material variously prepared. Here we find a very different con- 
dition from that described in the preceding section and one that 
is very instructive from the standpoint of the functional factors 
which have operated in the morphogensis of the vertebrate cere- 
bral hemisphere. 
In the frog the vomeronasal organ as defined by Gaupp is a 
small diverticulum from the medial side of the inferior chamber 
