THE BRAIN. BAT 
retically and practically it is important to recognize that the 
value of vision, indeed, the extent to which we “see,” is in no 
small degree related to what we feel. The carpenter judges dis- 
tances well by his eye, because he is constantly correcting his 
visual judgments by his tactile sense, his muscular sense, etc. 
We must point out, however, that the special developments 
of disease at the present day point to the dangers of an undue 
use or development of the cerebrum. That balance indispen- 
sable for health must be preserved, if the race is to avoid degen- 
eration. 
Synoptical—_There is as yet no systematized clear physiology 
of “the brain.” We are conversant with certain phenomena 
referable to this organ in a number of animals, chiefly the 
higher mammals; but our knowledge is as yet insufficient to 
generalize, except in the broadest way, regarding the functions 
of the brain—i.e., to determine what is common to the brains of 
all vertebrates and what is peculiar to each group. Referring, 
then, to the higher mammals, especially to the dog, the cat, the 
monkey, and man, we may make the following statements: 
The medulla oblongata is functionally the ruler of vegeta- 
tive life—the lower functions; and so may be regarded as the 
seat of a great number of “centers,” or collections of cells with 
functions to a large degree distinct, but like close neighbors, 
with a mutual dependence. 
Phylogenetically (ancestrally) the medulla is a very ancient 
region, hence the explanation apparently of so many of its 
functions being common to the whole vertebrate group. 
Parts of the mesencephalon, the pons Varolii, the optic lobes 
or corpora quadrigemina, the crura cerebri, etc., are not only 
connecting paths between the cord and cerebrum, but seem to 
preside over the co-ordination of muscular movements, and to 
take some share in the elaboration of visual and perhaps other 
sensory impulses. 
The cerebellum may have many functions unknown to us. 
Its connections with other parts of the nerve-centers are numer- 
ous, though their significance is in great part unknown. Both 
pathological and physiological investigation point to its hav- 
ing a large share in muscular co-ordination. 
It is certain that the cerebrum is the part of the brain essen- 
tial for all the higher psychic manifestations in the most ad- 
vanced mammals and in man. 
The preponderating development of man’s cerebrum ex- 
plains at once his domination in the animal world, his power 
