THE WASATCH FAUNA. 
275 
eight years ago by Prof. Edouard Lartet, of Paris. He states* “that it is 
the result of a number of investigations undertaken in different horizons of 
the Tertiary strata, that the more we follow the Mammalia into the antiquity 
of geological time, the greater is the reduction of the volume of the brain 
in comparison with the size of the head and the total dimensions of the 
body. Cuvier observed the form of the brain of the Anoplotlierium in a cast 
of marl, which was consolidated within the cavity of a skull of this animal, 
found in the gypsum of Montmartre. He says ;* ‘ It has little volume, and 
is flattened horizontally; the hemispheres do not present convolutions, but 
we find only a shallow, longitudinal impression on each. All the laws of 
analogy authorize us to conclude that our animal was greatly deficient in 
intelligence.’ In fact, the skull of the Anoplotlierium is six times as long as 
the cast of its cerebral hemispheres, and this animal, whose dimensions 
Cuvier compared to those of a medium-sized Ass, had a brain smaller than 
that of the existing Poebuck. 
“ I owe to the kindness of Professor Noulet, of Toulouse, the posses¬ 
sion of a fossil cranium, in which I have found the cast of a brain still more 
ancient than that of the Anoplotlierium of Montmartre, since the fragment 
comes from the Eocene of the Lopliiodon of Issel. In the brain of this ani¬ 
mal (which I call provisionally Bracliyodon eocoenus^ on account of the 
slight elevation of the crowns of the molar teeth), there are no longer any 
convolutions, but onlj^ certain irregularly-defined folds; the olfactory lobes 
are much prolonged in front, and the cerebellum is entirely separated from 
the hemispheres. This brain is smaller in all respects, and less complicated 
in its structure, than that of the Ccenotlierium described by Gratiolet; but 
it must not be forgotten that the latter animal is from a formation much 
more recent; that is, the Inferior Miocene of Allier. 
“ In proportion as we approach the present period, the differences 
between the fossil brains and those of living species become less marked, as 
has also been observed with reference to the elevation of the crowns of the 
molars. Thus the Deer and the Antelopes of the Middle Miocene of San- 
san present many convolutions, while the cerebellum remains moderately 
uncovered, and the olfactory lobes are very prominent. In the Superior 
*Comptes Reudiis, June, 1868. 
* Ossemens Fossiles, iii, p. 44. 
