FEBRUARY 11, 1897 | 
NATURE 
and Ist, IInd, and IIIrd thoracic. Of these, the VIIIth cervical 
is the only one which includes the whole of the surface of the 
free apex of the limb; its distribution in this respect closely 
resembles that of the VIth lumbar sensory root in the pelvic 
limb. 
The IInd section of the communication deals with the degree 
of conformity between the distribution of the spinal ganglion 
fibres in the skin and their distribution in the underlying deep 
tissues of the limb. It is shown that, although the séz fields of 
the ganglia are in the middle of the limb region dislocated from 
the median line of the body, the fibres of the root ganglion 
are nevertheless, when their deep distribution is taken into 
account, distributed to a complete ray of tissue extending in an 
unbroken fashion from the median plane of the body out along 
the limb to (in the case of the nerves, extending furthest into the 
limb) the very apex of it. This distribution conforms, therefore, 
with that shown in a previous paper to be typical of the distri- 
bution of the ventral (motor) root. The distinction is not, there- 
fore, as between afferent and efferent, but as between cutaneous 
and muscular. A detailed analysis of the distribution of the 
deep sensory fibres is in this paper carried out for the VIth 
lumbar spinal ganglion of Macacus rhesus ; this ganglion was 
chosen because its skin-field, occupying the free apex of the 
lower limb, is one as far dislocated from the median line of the 
body as any in the whole spinal series, and presents, therefore, 
the greatest apparent discrepancy between the distribution of 
its afferent and efferent roots. A comparison of the distribution 
of the afferent and efferent roots in this (VIth lumbar) nerve was 
made by means of the Wallerian method ; the results show the 
peripheral distribution of the two to be minutely similar. From 
this, and from other observations given, the rule is put forward 
as a definitely established one that the sensory nerves of a 
skeletal muscle in all cases derive from the spinal ganglion (or 
ganglia) corresponding segmentally with that (or those) contain- 
ing the motor cells, whence issue motor nerve-fibres to the 
muscle. The reflex arc, in which the afferent and efferent nerve- 
cells innervating a muscle are components, need not, therefore, 
as far as anatomical composition is concerned, involve irradiation 
through more than a single spinal segment. 
Section III. deals with general features of arrangement 
recognisable in the distribution of the roots. —Comparison 
between the human brachial plexus and that of Macacus is made, 
and it is pointed out that the human plexus is slightly prefixed, 
as compared with that of Macacus. 
Finally, in Section IV., various spinal reactions are examined, 
especially with reference to their effects upon the size and other 
features of the areas of the root-fields, &c., and the results 
collated and discussed. 
“* Cataleptoid Reflexes in the Monkey.” By C. S. Sherring- 
ton, F.R.S., Holt Professor of Physiology, University College, 
Liverpool. Received December 29, 1896. 
The reflex movements, the subject of this note, are of 
extremely prolonged duration, and absolutely devoid of clonic 
or alternating character. If the cerebral hemispheres be 
removed e.g. from a monkey, and if a finger of one of the 
monkey’s hands be stimulated, for instance, by dipping it into 
a cup of hot water, there results an extensive reflex reaction 
involving movement of the whole upper limb. The wrist is 
extended, the elbow flexed, the shoulder protracted, the upper 
arm being drawn forward and somewhat across the chest. The 
movement occurs after a variable and usually prolonged period 
of latent excitation. The movement, although it may be fairly 
rapid, strikes the observer each time as perfectly deliberate ; it 
is of curiously steady and ‘‘smooth” performance. Sometimes 
it is carried out quite slowly, and then, asa rule, the extent of 
itis less ample. The most striking feature of the reflex is, 
however, that when the actual movement has been accomplished 
the contractzon of the muscles employed in it does not cease or 
become superseded by the action of another group, but ts continued 
even for ten and twenty minutes at a time. The new attitude 
assumed by the limb is maintained, and that too without clonus 
or even tremor. In the instance cited, namely, that of the fore 
limb, the posture assumed suggests the taking of a forward step 
in quadrapedal progression, and in that posture the animal will 
remain for a quarter of an hour at a time. 
The degree of, for instance, flexion assumed in the new pos- 
ture seems much dependent on the intensity and duration of the 
stimulus applied. If the degree is extreme, the attitude of the 
limb may not be maintained to its full extent for the time men- 
tioned ; thus, the elbow, at first fully flexed, will in the course 
NO. 1424, VOL. 55] 
of a minute or so be found to have opened somewhat. This 
opening can be often seen to occur fer saltum, as it were, but 
the steps are quite small, and recurrent at unequal intervals of 
between perhaps a quarter of a minute anda minute. After 
some relaxation from the extreme phase of the posture has 
taken place, the less pronounced attitude, ¢.g. semiflexion at 
the elbow, may persist without alteration obvious to inspection 
for ten minutes or more, Apart from the occasional step-like 
relaxations, the contraction of the muscles is so steady as to 
give an even line when registered by the myograph. A renewed 
stimulation of the finger excites further flexion, which is main- 
tained as before in the way above described. The posture can 
be set aside without difficulty by taking hold of the limb and 
unbending it; the resistance felt in the process of so doing is 
slight ; the posture thus broken down is not reassumed when 
the limb is then released. 
Analogous results are obtainable on the hind limb. Hot 
water applied to a toe evokes always, so far as I have seen, 
flexion of ankle and knee; usually of hip also. This movement 
is ‘* deliberately’ executed, and always institutes a maintained 
posture. 
Not the least interesting part of the reflexes under considera- 
tion is a remarkable glimpse which they allow into the scope of 
reflex inhibition as regards the coordinate of movements of the 
limbs. Although the posture taken up by the right fore limb 
consequent upon excitation of a finger is symmetrically 
duplicated by the left limb when both hands are simultaneously 
stimulated, the effect of excitation of the two hands does not 
lead to symmetrical posture if the excitation be not synchronous 
but successive. If when the right arm has already assumed 
its posture in response to an excitation of the right hand, the 
left hand be stimulated, there results, while the left arm in 
obedience to the excitation is lifted and placed in the flexed 
posture, an immediate and, if the stimulus be at all more than 
slight, complete relaxation of the right arm. The right arm 
drops flaccid, while the left is raised and maintained in the 
raised attitude. Similarly, excitation of the right foot breaks: 
down the posture assumed by the right arm, and conversely, and 
even more easily, stimulation of the right hand breaks down a 
posture assumed by the right leg. Again, a nip of the right 
pinna causes relinquishment of a posture assumed by the right 
arm or by the right leg. If the right pinna is pinched when 
both arms are in this cataleptoid posture, complete inhibition 
can be readily exerted on the right arm, but usually only partial 
relinquishment can be induced in the left arm. To exert com- 
plete inhibition upon the posture of the left arm, the pinna 
pinched must be that of the left side. Similarly the posture 
reflexly: evoked by appropriate stimulation of either hind limb . 
can be inhibited by excitation of either pinna or of either fore 
limb, but predominantly by pinna and fore limb of the same 
side as the limb to be inhibited. The inhibition of the hind 
limb is much more easily elicited from the opposite hind limb - 
than from the opposite fore limb or opposite ear. I have- 
never yet seen it obtained diagonally upon the fore limb from, 
the opposite hind limb, 
February 4.—‘‘ On Lunar Periodicities in Earthquake Fre- 
quency.” By C. G. Knott, Lecturer on Applied Mathematics, 
Edinburgh University (formerly Professor of Physics, Imperial 
University, Japan). Received November 4, 1896. 
General Conclustons.—The conclusions are summarised under 
eight heads. 
(a) There is evidence that the earthquake frequency in Japan 
is subject to a periodicity associated with the lunar day. 
(4) The lunar half-daily period is particularly in evidence, 
both by reason of its relative prominence and the regularity 
with which, in each of two groups of the several seismic dis- 
tricts, its phase falls in relation to the time of meridian passage 
of the moon. 
(c) There is no certain evidence that the loading and unload- 
ing due to the flow and ebb of ocean tides have any effect on 
seismic frequency. 
(d) Hence we must look to the direct tidal stress of the moon, 
in its daily change, as the most probable cause of a range in 
frequency which does not exceed 6 per cent. of the average 
frequency. 
(e) There is distinct evidence, both as regards amplitude and 
phase, of a fortnightly periodicity associated with the times of 
conjunction and opposition of the sun and moon. 
(7) No definite conclusion can be drawn from the apparent 
monthly and fortnightly periodicities which seem to be 
