515 
In two animals they still existed, though very much weakened, 
Through section we ascertained the full accomplishment of the operation. 
From this it follows that the reflex curve for the tonic cervical 
reflexes runs mainly through the sensitive roots of Nn. cervicalis 
1 and 2, but that in some rabbits also the n. cervicalis 3 still contains 
centripetal fibers for these reflexes. 
D. The reciprocal innervation of the eye-muscles attending 
the tonic cervical reflexes. 
SHERRINGTON’S researches ') have tended to show that contractions 
of definite eye-muscles are attended with relaxation of the antago- 
nists. BartTELs’) was able to demonstrate the same for various 
forms of nystagmus. 
The tonic eye-reflexes seemed to us just the proper object to ascertain 
this for these reflexes and to register it graphically. 
Registration of the tonic labyrinth reflexes is very difficult, because 
the head must continually be brought into another position in space. 
With tonic cervical reflexes the matter is quite different: then the 
head is firmly fixed and the movements are carried out with the 
trunks. 
Our procedure was as follows: tracheotomy was performed in 
ether-narcosis, the carotids were ligated, the vagi cut. Then a prepa- 
ration was made of the Mm. internus and externus of one eye, a 
thread was fastened to the muscles at the place of insertion to the 
bulbus; subsequently the muscles were severed from the bulbus. 
After this the bulbus was extirpated together with the other eye- 
muscles; then the muscles were separately connected by the thread 
over a pulley to a lever, which enabled us to register the contractions 
on a Kymograph. The whole arrangement, as will be seen, was like 
the one described by Barters. During the experiment the ether- 
narcosis was continued, or, what was more satisfactory, it was stopped 
after the two cerebrum-hemispheres bad been removed (thalamus- 
animal after Manus). 
The graphical representation of such an experiment with a thala- 
mus-animal is seen in Fig. 2. The upper line registers the con- 
tractions of the M. rectus int.; the lower line of the M. rectus ext. 
of the left eye. 
1. We started from: Animal in ventral position, mouth-fissure 
1) SHERRINGTON. Proceedings Royal Society 53, 407. 
3) Bartets. Graefe’s Archiv. Mitteilung I—IV. 76, 77, 78 and 80. 
