80 W. H. TALIAFERRO 
In experiments on decapitated and normal Planaria torva, 
Parker and Burnett concluded (p. 385): 
Planarians without eyes react to the directive influence of light in 
much the same way as those with eyes, in that they have a tendency 
to turn away from the course when directed toward the source of light 
and to keep in it when directed away from the source, though with 
less precision and often to less extent than planarians with eyes. 
Planarians with eyes move more rapidly (1.12 mm. to 1.04 mm. per 
sec.) than those without eyes (0.89 to 0.82 mm. per sec.) and those 
moving away from the light (1.12 mm. and 0.89 mm. per sec.) than 
those moving toward it (1.04 mm. and 0.82 mm. per sec.) 
Opposed to these results we find that Lillie (01) maintains 
that posterior headless pieces of Dendrocoelum lacteum do not 
exhibit the usual responses to light. Also, Mast (10) main- 
tains that an undetermined marine turbellarian with the eyes 
removed fails to orient to a horizontal beam of light, while nor- 
mal specimens orient fairly precisely. 
The present experiments on the reactions of specimens with 
both eyes removed were designed to answer two questions: 1. 
Does removal of the eyes affect the character of the responses 
to light? 2. Does removalof the eyesaffect the rate of locomotion? 
The animals used in these experiments were anesthetized and 
their eyes cut out in the manner described in the section on 
methods. After each animal was operated on, it was allowed 
approximately twenty-four hours to recuperate. If, after this 
time, the animal showed any distortion about the head it was 
discarded. Then, as a further check, each animal was, after 
the experiment, fixed, sectioned, and stained. These sections 
were carefully examined, and the records of any animal were 
discarded if the sections contained any trace of the eye which was 
removed or if there was any deep cut into the ‘brain.’ 
By using this technique it is surprising how neatly a small 
organ like the eye can be removed. In successful operations, 
the only noticeable difference from normal specimens besides 
the absence of the eyes is a slight dislocation of the pigment of 
the body surface in this region (fig. 7). In some cases even this 
cannot be detected. The sections, in the majority of cases, 
revealed the fact that the ‘brain’ had not been cut at all in the 
