1907.] Innervation of Antagonistic Muscles. 341 



nerve of a muscle whose own nerve inhibits (refiexly) that muscle itself would 

 also inhibit the other muscles whose nerves refiexly inhibit their own muscles. 

 Experiment shows this to be actually the case. Thus the afferent nerve of 

 vasto-crureus inhibits refiexly the gastrocnemius ; the nerve of gastrocnemius 

 inhibits refiexly the vasto-crureus ; the nerve of soleus inhibits vasto-crureus, 

 the nerve of vasto-crureus inhibits the soleus, and so on, so far as I have 

 tested. 



Similarly, stimulation of the afferent nerve proceeding from a muscle whose 

 nerve throws its own muscle refiexly into contraction might be expected to 

 excite reflex contraction in other muscles whose afferent nerves excite reflex 

 contraction in their own muscles. Experiment finds this to be actually the 

 case. Thus the nerve of semi-tendinosus excites, refiexly, contraction of the 

 tibialis anticus ; the nerve of tibialis anticus excites reflex contraction in the 

 semi-tendinosus ; the nerve of extensor longus digitorum excites reflex con- 

 traction in the tibialis anticus ; the nerve of tibialis anticus excites reflex 

 contraction in the extensor longus digitorum ; the nerve of psoas excites 

 contraction in the semi-tendinosus; the nerve of semi-tendinosus excites 

 contraction in the psoas ; the nerve of psoas excites contraction in the tibialis 

 anticus ; the nerve of tibialis anticus excites contraction in the psoas, and so 

 on, so far as my experiments go. 



IV. The reflexes elicitable from some of the limb nerves other than the 

 above have also been observed in the experiments (cat). Among these 

 additional nerves have been the following : the first dorsal digital, external 

 plantar, internal plantar, the branch from the anterior tibial trunk to the 

 foot (taken close above the ankle), the cutaneous branch of the musculo- 

 cutaneous division of the peroneal nerve, the external saphenous nerve on 

 the calf, the cutaneous branches of the sciatic given off above the popliteal 

 space, the branch of the obturator to pectineus, the branch to gracilis, the 

 branch to the adductor, the whole obturator nerve at the obturator foramen, 

 the external cutaneous and the internal saphenous at various points along its 

 course. These evoke reflex contraction in psoas, semi-tendinosus, biceps cruris 

 (posterior part), tibialis anticus, extensor longus digitorum, peroneus longus — 

 the reflex contraction in these two last is relatively slight, in my experience — 

 gracilis, sartorius, tensor fascia? femoris, gluteus maximus (anterior part), 

 gluteus minimus, pectineus. The muscles, therefore, in which the reflex 

 contraction has been observed to take place may be broadly described as those 

 producing flexion of the limb, with some abduction and inward rotation. 

 Consonantly with this, the reflex movement observed to result from 

 stimulation of each of the afferent nerves, mentioned in the list at the outset 

 of this section, has been flexion at knee, hip, and ankle, the flexion tending 



