THE BRAIN. 499 
is not more intimate than that established in that great collec- 
tion of organs crowded together and making up the brain. 2. 
Since the relative size, position, and anatomical connections of 
the parts that make up the brain are different in different 
groups of animals, not to speak of the fact that the functions 
of any part of the brain of an animal, like that of its spinal 
cord, already alluded to, must depend in great part upon its 
own and its inherited ancestral experiences, it follows that the 
greatest caution must be exercised in applying conclusions 
true of one group of animals to another. As we shall point 
out, the neglect of this precaution has led to needless contro- 
versy and much misunderstanding. 3. It follows, from what 
has been referred to in 1 above, that conclusions based upon the 
behavior of an animal after section or removal of a part of the 
brain must be, until at least corrected by other facts, received 
with some hesitation. 4. It also might be inferred from 1 that 
it is desirable to study the simpler forms of brain found in the 
lower vertebrates, in order to prepare for the more elaborate 
development of the encephalon in the higher mammals and in 
man. 5. The embryological development of the organ also 
throws much light upon the whole subject. 
The student will see from these remarks that a sound knowl- 
edge of the anatomy of the brain and its connections is indis- 
pensable for a just appreciation of its physiology; nor must 
such knowledge be confined to the human or any other single 
form of the organ. There is only one way by which this can 
be attained: dissection, with the help of plates and descriptions. 
The latter alone frequently impart ideas that are quite errone- 
ous, though they serve an especially good purpose in helping to 
fix the pictures of the natural objects, and in reviving them 
when they have become dim. 
It is neither difficult to obtain nor to dissect the brain of the 
fish, frog, bird, ete. Valuable material may be saved and the 
subject approached profitably, if, prior to the dissection of a hu- 
man brain, a few specimens from some group or groups of the 
domestic animals be examined. However useful artificial brain 
preparations may be, they are so far from nature in color, con- 
sistence, and many other properties, that, taken alone, they cer- 
tainly may serve greatly to mislead; and we hope the student 
will allow us to urge upon him the methods above suggested 
for getting real lasting knowledge. The figures given below 
may prove helpful when supplemented as we advise. 
The great difference in total size, and in the relative propor- 
