132 THOMPSON YATES LABORATORIES REPORT 
inner hamstrings and often the graciHs seem to play a predominant part when the skin stimulated 
is of foot or leg, the outer hamstring when the middle or back of thigh. I have seen flexion of 
the knees with abduction of the thighs result from stimulation of the entrance to the vagina. 
Depression of the tail is elicitable from the skin above the ischial callosity. Defaecation can be 
sometimes induced by stimulation of the anal opening; it is accompanied by elevation of the tail 
and to and fro and side to side movement of it. A curving downward of the end of the tail is 
obtainable as an isolated movement from the skin of the ventral surface of the tail distal to the 
root. Protrusion of the anus is elicitable from a large field, i.e.^ from the perineum around the 
anus and along the side of the vaginal orifice, also from over tlie back of the sacrum up to, but 
not beyond, the position of my doruil line* of the limb, and from the extreme top of the inner 
aspect of the thigh, near the raphe and beside the pubic fold. There and along its lateral border, 
this anal reflex field overlaps the reflex field of the hallux. 
Flexion of the hip, apparently unaccompanied by flexion of the knee, comes to be elicit- 
able from the femoral triangle, and, broadly speaking, from the whole front of the thigh ; not 
infrequently associated with this flexion of the hip is adduction, and also adduction with slight 
extension of the opposite knee. 
From the tibial side of the sole and hallux inversion of the foot, never, perhaps, as an 
isolated movement, generally associated to flexion of hallux with movement of the other digits, i 
may be elicitable. From the fibular side of the sole, and from the small digits, aversion of the^ 
foot, never as an isolated movement, but generally associated to digital movement. Similarly, in 
the forearm, excitation of the skin of the little finger sometimes elicits some pronation with the 
flexion of elbow, while from the tliumb some supination with the flexion of elbow is usual. 
Primary dorsal, more often than primary plantar flexion of ankle accompanies flexion of knee. 
Flexion of hip, more often than extension of hip, goes with flexion of knee. Extension of knee 
is a movement of such rare occurrence as to be, as a local homonymous reflex,t hardly seen in 
most Cats and Monkeys in my experience. Adduction of the hip is much less uncommon, and 
among crossed reflexes is common ; in one animal it was regularly elicitable without other move- 
ment, or with slight extension of knee, as a crossed reflex from the skin near the raphe and 
pubic fold. It is not unfrequent to find that from some part of the sole can be evoked flexion of 
the small digits even when from most of the sole extension of them (at the metatarso-phalangeal 
joints) is elicited ; generally the area for flexion lies on the fibular side of the sole. 
The above stated degree and multiformity of reflex action having been attained, feeble 
and poverty-stricken as it is, I have never seen any further progress made. The longest periods 
through which I have maintained individual experiment have been six months and five months 
respectively. Not a little surprising is it to find that the movement which, on account of its being 
the most easily evoked and the one evoked alone when depression of reflex activity is great, may 
be called the primary spinal reflex of the limb, is the very movement which has been often urged 
to be par excellence the most eminently cortical one, namely flexion adduction of hallux. I have 
* See above, Section III. 
-f- i.e., a reflex elicited by excitation of the limb itself. 
