8 JOURNAL OF COMPARATIVE NEUROLOGY. 
portion known as the putamen, and two inner divisions called 
the globus pallidus. In carnivores no such division exists. 
The corpus callosum of Macacus is very short. It pre- 
sents, however, a well-developed forceps major and a forceps 
minor. The nerves of Lancisi are also plainly discernible. 
These cannot be differentiated in the dog. The splenium of 
the corpus callosum sends off a thick bundle of fibres which 
fuses with the hippocampus of both sides and serves as a com- 
missure between them. 
The anterior commissure is more extensive than in carni- 
vores. It runs into the temporal lobe. Its termination can be 
ascertained only by microscopic methods. 
The Third Ventricle. 
The cavity of the third ventricle is extremely small and 
narrow. This is due to the fusion across the median line of 
the large optic thalami, which are continuous with one another 
throughout their length except inferiorly. This fusion across 
the median line represents the middle commissure of man. 
From this brief macroscopic study of the fore brain of 
Macacus we see that the simian brain closely resembles that of 
man; for Macacus seems to present most of the conditions 
existing in man, the sole difference in most instances being one 
of degree. 
DESCRIPTION OF PLATES. 
PLATE I. 
fig. z. The external surface of the left hemisphere of Macacus rhesus. 
fig. 2. Mesial surface of left hemisphere of Macacus rhesus. 
PLATE II. 
fig. 7. Mesial surface of the left hemisphere of Macacus nemestrinus. 
fig. 2. External surface of cerebrum of Macacus nemestrinus. Part of 
the occipital lobe has been removed to show the annectent gyri. 
