1892,] Brain Centres. 735 
duced paralysis or loss of ability to voluntarily perform these 
same motions. Tumors or the rupture of blood vessels in these 
brain regions also cause these paralytic conditions and confirm 
the results of experimentation. 
Destruction of other portions of the brain enabled the local- 
izing of centres for the special senses, and thus we have ascer- 
tained that the optic centre is in the hindmost tip of the 
cerebrum, the auditory is two or three inches farther forward. 
The centres thus far accurately located are those for sight, and 
hearing and those controlling the motions of all parts of the 
extremities, the head, and the vocal apparatus. 
Notwithstanding the large size of the olfactory tract at its 
junction with the brain the smelling centre has not yet been 
undisputedly made out. There are many portions of the brain 
the functions of which have not been discovered because pres- 
ent methods of observation are insufficient. There are certain 
phenomena that follow upon injury of other portions, such as 
loss of sensation, elevation of bodily temperature, incoérdina- 
tion, vertigo, but, as any one of these kinds of disturbances may 
be produced by injury to several different areas, strictly speak- 
ing we cannot regard such pathological processes as indicating 
physiological centralization. 
The clustering of certain motor nerve beginnings for coördi- 
nating processes into closely aggregated nuclei, warrant, to a 
qualified extent, such terms as crying, laughing, sneezing, and 
vomiting centres, and as laughing and crying are regarded as 
emotional exhibitions, the conclusion has been jumped at that 
the medulla, where these nuclei are found, is the emotional 
centre. Then there is a sort of hazy idea derived from phreno- 
logical assumptions, that there is a centre for memory, another 
for sexuality, others for combativeness, mathematics, and so 
on. 
Examining by reasoning processes certain faculties that 
are dependent upon brain integrity, we may arrive at conclu- 
sions that are valuable from both positive and negative points 
of view. The negations afforded by science make us intellectu- 
ally superior to superstition, though they may not, for the 
nonce, give us “ something else instead ” of our fetiches. 
