88 W. H. TALIAFERRO 
In these experiments, exactly the same technique was employed 
and the same precautions were observed as in the experiments 
of the preceding sections. The animals were anesthetized with 
CO, and one eye removed with a fine knife, as has been described 
(fig. 7). After the removal of an eye, the animals were given 
eight to twenty-four hours to recover from the operation. At 
this point any specimen which showed any distortion of the 
head or any loss of the bilateral symmetry of the contour of the 
anterior end was discarded. It is to be noted that in removing 
one eye there is more tendency to disturb the bilaterally symmetri- 
cal contour of the anterior end than in the case where both eyes 
are removed. <Any disturbance of the contour of the head is 
often followed by abnormal locomotor disturbances. After each 
experiment, the animals were fixed, sectioned, and stained as in 
the preceding section. Again, the records of all animals in 
which there was any injury to the ‘brain’ or incomplete removal 
of the eye were discarded. 
When observed in non-directive light, specimens with one eye 
removed travel about, apparently, in every respect like normal 
individuals. In neither directive nor non-directive light is there 
any evidence of sluggishness, circus movements, or other abnor- 
mal motor activities. The absence of circus movements is in 
marked contrast to the results of Mast (’10, p. 132). 
In studying the process of orientation in specimens with one 
eye removed, the paths of twenty-nine individuals were traced 
by means of a camera lucida. All of these tracings are essen- 
tially like the one reproduced in figure 9. This tracing was made 
from observations on a specimen twenty-four hours after the 
right eye had been removed. Just prior to the removal of the 
eye the specimen oriented accurately when illuminated laterally 
on either side. ‘The tracing shows that after the removal of the 
eye the animal oriented immediately and precisely like normal 
specimens whenever the direction of the rays of light was changed 
so as to illuminate the normal side (fig. 9, V); but when the 
‘blind’ side was illuminated, it did not react immediately nor 
did it orient like normal specimens. In two cases when the 
‘blind’ side was illuminated, viz., after light 1 and 3 were turned 
