1890] * Physiology. 195 
In a paralytic the left knee-jerk was wanting, and the right was present 
with motor reinforcement only. Post-mortem investigation of the 
spinal cord revealed marked degeneration of fibres in’ the region of the 
entering posterior roots of the lower dorsal and upper lumbar sections 
on the left side, less on the right side; the fibrous portion of Clark’s 
columns was more atrophied on the left than the right, also the left 
posterior roots in places. This confirms yee Ad localization of the 
centre for the knee-jerk. 
Heat-centres.—The localization and even the existence of heat- 
centres in the human central nervous system is still in dispute. Ac- 
cording to Ott,! six such centres, injury to which is followed by in- 
crease of temperature, have been localized in the lower animals. These 
are the cruciate in the region of the fissure of Rolando, the Sylvian, 
at the junction of the supra and post-sylvian fissures, the caudate 
nucleus, the region about the corpora striata, a point near the median 
line between the corpora striata and the optic thalami, and the an- 
terior inner end of the optic thalami. Ott has collected a number of 
clinical cases as evidence of similarly located heat centres in man. 
The high temperature usually following lesions of the spinal cord, me- 
dulla oblongata, or pons varolii, is explained as due to a removal of 
the influence of the thermotoxic centres allowing spinal thermogenesis 
to become exaggerated. 

At a recent meeting of the Neurological Society of London, 
when pyrexia was under discussion, Victor Horsly® gave some results 
of observations on the differences of temperature of the two sides of 
the body as symptomatic of cerebral lesions. He states that in 18 
cases lesions of the ‘‘ corpus striatum frontal plane of the hemisphere,’’ 
which reaches the brain surface in the ascending frontal gyrus, was 
followed as a rule by increased rise of temperature in the opposite side 
of the body; lesions in other parts of the hemisphere were not so 
followed. He deprecated the use of the term ‘‘heat-centres,’’ until 
the matter had been more fully investigated by experiment. 
At the same meeting Dr. W. Hale White’ gave an account of his 
researches on the influence on bodily temperature of lesions of the 
corpora striata and optic thalami. Rabbits were used for experiment, 
and the lesions were made by trephining the skull and inserting a wire 
in such a manner that portions of the central ganglia could be de- 
5 Brain, sey XLIV., 1889, p. 433- 
ê British Medical Journal, Vol. I. for 1889, p. 1406. 
1 British ent Journal, Vol. I. for 1889, p. 1401. 
Nat.—February.—6. 
