456 Miss Tozer and Prof. Sherrington. Receptors and [May 18, 



and that to inferior oblique sixteen sound fibres, all of minute size. The 

 fourth nerve entering superior oblique showed a certain number of 

 degenerate fibres, some large, but in the main the nerve was sound. The 

 short ciliary nerves were found to be entirely free from degeneration. 



(2) Muselef!. — No nerve-endings were discoverable in any of the muscles 

 except superior oblique, which latter showed them without any obvious 

 departure from the normal. From the remaining muscles tlie nerve-endings 

 had all disappeared, and the tendon nerves also were gone, though in the 

 tendon of internal rectus one sound nerve-fibre persisted, and in that of 

 superior rectus four, and in that of inferior rectus six. 



(Regarding levator ijalpchrcv in this and tlie other experiments we are 

 reserving our remarks for a fuller account than the present communication 

 allows.) 



Conclusions. 



After severance, therefore, of the third nerve at its origin, not only do 

 the motor-plate endings disappear from superior, inferior and internal recti 

 and inferior oblique muscles, but the musculo-tendinous and intramuscular 

 receptive (sensorial) nerve-endings also disappear from these muscles, together 

 with the afferent nerve-fibres supplying them. 



Similarly with the superior oblique muscle after intracranial severance of 

 the fourth nerve. Similarly with the external' rectus muscle after intra- 

 cranial severance of the sixth nerve. 



The iifth nerve may send a few fibres to the muscles in the orbit, but this 

 supply in rabbit, cat, and monkey is insignificant in amount. 



A few sparse myelinate fibres of minute size {2 [x — o ix) still persist 

 undegenerate in the extrinsic eye muscles after combined severance of the 

 third, fourth, and sixth nerves, and of the ophthalmic division of the lifth ; 

 some of these pass into the tendons of the muscles. Their source appears to 

 be tJie ciliary ganglion, and in tlie case of tlie inhu'ior ol)lique muscle a small 

 accessory ganglion lying in the nerve of that muscle, sometimes (piite close 

 to the entrance of the nerve into the muscle itself. The ciliary ganglion is, 

 as Langley and Anderson* have shown, entirely an efferent relay station, 

 and is the equivalent, as (laskellf poinUul out-, of a sympathetic ganglion. 

 That it contains no cells equivalent to those of the s])inal root-ganglia seems 

 certain from the absence of sound liljres in the intracranial stumps of third, 

 fourth, or sixth nerves, distal to their intracranial severance. The few sparse 

 minute niy(;liiia,tc libres probably of ciliary source which, in the orbit, lind 



* '.Jouni. of I'liysiol.,' vol. 17, p. IHI, IHDJ ; Ibid., vol. ;J2, p. 17:3. 

 t '.Journ. of J'liy.siol.,' vol. 10, ].. 1 5:j, 188!). 



