REACTIONS TO LIGHT IN PLANARIA MACULATA 81 
removal of the eyes. Throughout this series of experiments it 
was found essential never to use specimens which showed any 
distortion of the head. Such distortions are often followed by 
abnormal motor activities. 
1. Character of reactions to light. Specimens with both eyes 
removed move about essentially like normal specimens. They 
exhibit the twisting reflex (p. 75) and occasional ‘wigwagging 
movements’ (p. 72) just as do normal specimens. When 
observed in non-directive light, no difference can be observed 
between them and normal specimens in either the rate or nature 
Fig. 7 Photographs fromunretouched negatives of normal and operated speci- 
mens. All magnified 30 diameters. A, normal specimen; FL, eyes; B, specimen 
with both eyes removed; C, specimen with left eye removed; EH, eye. Note the 
lack of distortion in those specimens which have been operated on. 
of locomotion. This is in marked contrast to the behavior in 
decapitated worms. 
Although no difference can be detected between the reactions 
of normal specimens and specimens with both eyes removed 
when in non-directive light, this is not the case when observed 
in directive light. Specimens with both eyes removed do not 
orient to a horizontal beam of light as do normal specimens. 
This is well illustrated in the following detailed description of 
one of the twenty experiments made, the results of which are 
essentially the same, 
