No. 5.— CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY 
OF THE MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD 
COLLEGE. E. L. MARK, Director. No. 223. 
The Reactions of Amphibians to Monochromatic Lights of Equal 
Intensity. 
By Henry LAURENS. 
TABLE OF CONTENTS. 
I. INTRODUCTION . 
Il. Merrxops 
i. nase eae 
A. The light eanentou 
B. The combined apparatus 
2. Material . 
III. OBSERVATIONS ; 
1. Reactions to sate a eu a ake : 
a 
Ho pad 
Reactions with both the skin and the eye as recep- 
tors 
Reactions with hic eye as one 
Reactions with the skin as receptor 
Reactions of normal toads compared with i ag 
toads from which the eyes had been removed . 
Summary 
2. eabions to palace pairs a cpaieclinarteitic net ; 
A. 
Cy 
IV. Discussion 
V. SUMMARY 
Lights of different wave-lengths 
a. Reactions with both the skin and the eyes as 
receptors 
b. Reactions with tid eyes as Re 
ce. Reactions with the skin as receptor 
Lights of the same wave-lengths 
Reactions with both the skin and ne eyes as 
receptors ee Pee ae aaa 
Summary 
VI. BIBLIOGRAPHY 
PaGE 
. 254 
258 
258 
259 
259 
263, 
264 
264 
264 
267 
269. 
272 
275 
277 
277 
277 
282, 
286 
289 
289 
290 
292 
299 
301 
