DR. D. EERRIER ON THE BRAIN OF MONKEYS. 
451 
blind in the sense in which I use the term may make when a light is flashed before 
its eyes. 
Retinal impressions and reflex actions resulting from these are left unaffected by the 
lesion which abolishes the perception of visual impressions. 
Effects of Lesions of the Temporo-sphenoidal Lobe. 
The experiments recorded under this heading relate to more or less general, as well as 
limited, lesions of the convolutions of this lobe. As it is difficult to reach and localize 
lesions in the individual convolutions, the exact effects of the destruction of any one 
part have to be arrived at in a great measure by a process of exclusion, besides that of 
direct experiment on each separate region. 
The effects of electrical stimulation have been already recorded. 
Irritation of the superior temporo-sphenoidal convolution always gave very definite 
results, viz. pricking of the opposite ear, opening of the eyes and dilatation of the pupil, 
with turning of the head and eyes to the opposite side. 
That these phenomena were the indications of excitation of subjective auditory sen- 
sations seemed probable, both from experiments on monkeys and other animals. 
Stimulation of the posterior division of the third external convolution in cats, dogs, 
and jackals is usually followed by sudden pricking of the opposite ear. In rodents a 
similar effect results from stimulation of an homologous region. 
A very marked effect I observed in the case of a wild jackal, on stimulation of the 
posterior division of the third external convolution. The animal suddenly started, 
pricking up both ears, and would have bounded off the table had it not been securely 
fixed. 
The phenomena were just such as would have resulted from a sudden alarm. A 
similar result I observed in a rabbit on which I was experimenting. 
That the movements resulting from irritation of the superior temporo-sphenoidal con- 
volution in monkeys resemble those caused by a sudden sound is seen by the following 
experiment : — 
A monkey was placed on a table, and a loud whistle made close to its ear. Imme- 
diately the ear became pricked up, the animal turned its head to the same side, opening 
its eyes widely, while the pupils were observed to be dilated. The dilatation of the 
pupils was not observed in every case when the experiment was repeated, but the other 
phenomena were the same. 
The effect of irritation of the lower end of the uncinate convolution (subiculum cornu 
ammonis), viz. torsion and closure of the nostril of the same side, is evidently to be taken 
as the indication of excitation of subjective olfactory sensations, and is precisely similar 
to the effect of irritating the olfactory bulb itself, as I have ascertained by direct 
experiment. 
The following experiments serve to demonstrate the accuracy of the views at which I 
had arrived. 
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