274 Cc. JUDSON HERRICK 
is represented in the mammalian presubicular area (and some 
contiguous tissue), evidently the name “pallial element of the 
amygdaloid complex” given to this region by Dart (’20, p. 18) 
is Inappropriate. 
The anatomical configuration and connections of the amygda- 
loid complex suggest that as a whole it possesses a certain physi- 
ological unity and that the component parts of this integrated 
complex are diversely represented in various vertebrate -types, in 
accordance with their respective modes of life. The amphibian 
relations suggest, further, that the correlation of olfactory, gusta- 
tory, and perhaps other excitations arising from food within the 
mouth was the original integrating physiological factor. The 
complex of higher forms probably includes also connections of 
the tactual and muscle senses.* Though the differentiation of the 
vomeronasal organ peripherally was the initial point of departure 
for the fabrication of the amygdala, the complex, once developed, 
retains its individuality in the absence of the vomeronasal organ 
(alligator, man), and even of the entire olfactory system (dolphin). 
The mammalian amygdala, like many other complex correla- 
tion centers, is a mechanism in which there converge into final 
common paths numerous very diverse kinds of peripheral excita- 
tion—some of visceral (interoceptive) type and some of somatic 
(exteroceptive) type. In some species one of these types may be 
dominant, in other species the other, and the analysis of these 
components must be carefully worked out in each vertebrate 
group before we can generalize profitably. In the Amphibia 
the visceral components are clearly predominant, and this appears 
to be the primitive situation. 
The vigorous and rather temerarious attack of Dart (20, p. 
18) upon this method of cerebral analysis is evidently based 
5 The tactual factor may in some animals be very important. In this con- 
nection it is interesting to note that Broman (’20, p. 178) considers that the 
forked tongue. of serpents is accessory to the vomeronasal organs which here 
are very large, the extruded tongue taking up odors and carrying them back to 
the openings in the roof of the mouth of the ducts of these organs, which in- 
deed the tips of the tongue may enter. The serpent’s tongue is generally re- 
garded as a very efficient tactile organ, and this function also, accordingly, 
would naturally be largely represented in the amygdaloid complex of serpents. 
