528 ANIMAL PHYSIOLOGY. 
night, by the facts above considered. It is, moreover, highly 
probable that not only different parts of the brain have a dif- 
ferent psychical function, but also that in any one chain of 
thought or state of consciousness only a certain number of parts 
are prominently engaged; and that what is termed confusion 
of mind is probably a result of the activity of certain other 
centers to a degree unusual—i,e., they are relatively too obtru- 
sive, hence that balance essential to all normal activity, psy- 
chical and other, is lost. 
Specialization, physiological division of labor, holds here as 
elsewhere. 
Hypnotism.—By the help of the above principles the subject 
of hypnotism, now of absorbing interest, may be in great part 
explained. This condition is characterized by loss of volition 
and judgment. It may be induced in man and certain other 
animals by prolonged staring at a bright object, assisted by a 
concentration of the attention on that alone, as far as possible, 
combined with a condition of mental passivity in other respects, 
The individual gradually becomes drowsy, and finally falls into 
a state in many respects strongly resembling sleep. With each 
recurrence, the hypnotic condition is usually more readily in- 
duced, and persons have passed into it in the entire absence of 
the usual procedure, having simply been told that they would 
be thus affected at a given hour. There is no special influence 
emanating from peculiarly gifted mediums, and most persons 
may be hypnotized to a greater or less degree, though with 
unequal readiness. 
The manifestations are very variable, but are usually char- 
acterized by either total abolition of certain sensory percep- 
tions, by their enfeeblement, or by one or both of these, com- 
bined possibly with exaltation of others. Thus, anesthesia 
may be so great that surgical operations may be performed 
without consciousness of pain. The muscular sense may be 
good, so that the subject can write well. He may smell better 
than usual, so as to be able to detect persons by the odors from 
a portion of their clothing, like a dog. There may coexist, with 
vision for form, color-blindness. These are to be regarded mere- 
ly asexamples, from numberless curious combinations. Again, 
the affection of sense may be bilateral or only unilateral. 
Hypnotism proper may be combined with catalepsy, a con- 
dition in which the limbs remain rigid in whatever condition 
they may be placed. Modifications of the vascular and respira- 
torv systems occur. Other animals have been hypnotized, as 
