120 
PROFESSOR OWEN 
CH. IV. 
partially adorned with it, and it was a curious 
fact that even very young whales had mustachios 
and whiskers. Again, all Mammalia had a com- 
plex heart, with ventricles and auricles, which 
received and circulated the blood. No other 
animals but those belonging to the class Mam- 
malia had a diaphragm. Cuvier had pointed 
out some other characteristics ; but there were 
m his system some apparent anomalies, such as 
ranking the mole higher than the lynx, the bat 
above dre dog, and even the duck mole of 
Australia he placed above the elephant. 
He (Owen) himself, from the examination he 
had made, arrived at the conviction that there 
were two or three, or perhaps four, well-marked 
steps in the development of the brain, and that 
the brain was the organ on the modifications and 
differences in the structure of which the Mam- 
malia should be divided. There were in all Mam- 
malia the little brain, or cerebellum, the optic 
lobes, in which the nerves going to the eye were 
chiefly rooted, the cerebral hemisphere, and 
the olfactory lobes, with which the nerves of 
smell were connected. In all the cold-blooded 
vertebrates, in reptiles, fishes, and birds, the cere- 
bral hemispheres were almost quite detached, 
there being nothing between them except a little 
cord, and this was the case with a certain por- 
tion of the Mammalia, which were called loose- 
brained, or, as Professor Sedgwick had quaintly 
