AUTHOR’S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, MAY 5 
REACTIONS TO LIGHT IN PLANARIA MACULATA,! 
WITH SPECIAL REFERENCE TO THE FUNCTION 
AND STRUCTURE OF THE EYES 
W. H. TALIAFERRO 
Zoological Laboratory of the Johns Hopkins University 
EIGHTEEN FIGURES 
CONTENTS 
Pe pEGHMCEIONE LE NGSt Ls ou eeee ee eee ceeded cote sonic deed bce tobe ge 60 
Msi be rials Mader e GAO Secrecy yaya ciorb oeauay ortse hae et aRLa OOS wstwNe blepz's foe's: obra tod eae 63 
PE RMe NUNEr Gib RE TOUO tr gel tgs Ns ctrl las Save cir Kasecsiccre' AAt uote <ictere shee sine Caleslote dae 68 
Orientation co light im normal specimens. ....... 2c ee. ccs eccecesucdeeks 12 
Orientation to a horizontal beam of light. ...................... Bahn, 72 
1. Extraneous reflexes during orientation........¢.........eeceecee% 74 
2. Character of turning in animals during orientation in different 
MILCHSIIES OL MIMMINAGION cine sccians Sasise s/s Se encjeue eb eosieie Uae 75 
RTC IOHMEE TG ECC VER: Me skies anes Semmes tone SU ee ee 79 
A. Reactions to light in specimens with both eyes removed............ 79 
Le Character of meachions tOsiplit cto: 4. .6h oh: <:<micree deprerte avo: 81 
Zesle MUL Ol OCOMM ELON: actress Vepaci Martian cade 8 ds. hi sew ademicte 84 
3. Discussion of experiments in relation to former investigations 86 
B. Reactions to light in specimens with one eye removed.............. 87 
CA iocglized:sensory. regions: im) thesey@ac2i3 02500 bs 028/40 owiateewies ak are 93 
1. Extent of localized sensory regions... . ...:,..... 22.0 cmadéeache- 93 
2. Reactions to light in specimens with one eye and the posterior 
half*of the otherieye'removed: 2... 102 e 98 
3 Reactions to light in specimens with one eye and the anterior |: 
half: ofuthe other Eve WemoOved.. «43 toes dhe scclesemteicsehcgneever aa 101 
PDE eocalizatvons OL photicrs timation sc caisc< qa cw eyes are a see ache ees. 102 
1. Mechanism of localization of photic stimulation.............. 102 
2. Localization of photic stimulation in relation to the structure 
CUEENG CNC. 3. 41 ue emer eS te cpeouty tnd} ois.e eG wc eleke bc ghonthein 107 
Nature of the stimulus Guring OFIENtAGION. 6.55 ici cure ce we cts. 0 «esses e.eiste sere 109 
OCSTOAEAD | SULETIE S23 eon ae eR ea de li A a i en 112 
JET CuCIGT@A32)] 0) ON Ze ised 0 a UO eae PURER Se A os a ay Re be OP PS SD a 114 
1 Although there is some uncertainty as to the species of Planaria used in the 
experiments recorded in this paper, it has been designated maculata. This ques- 
tion is discussed on page 64. 
59 
THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 31, No. 1 
