BEHAVIOR AND COLOR CHANGES OF TREE FROGS 77 



SUMMARY 



i. The species of tree frogs herein reviewed show on the 

 average a lightening of skin color in the presence of strong 

 light, but with marked exceptions. 



2. Darkness has not been found to have any appreciable effect 

 in relation to color changes. 



3. A high temperature seems to act much as strong light to 

 induce a proximal migration of chromatophores, hence to pro- 

 duce a lightening of skin color; but as in 1, with marked ex- 

 ceptions. 



4. A low temperature has not been found to have any direct 

 effect as to color changes. 



5. It has not been found that the nature of contact stimuli 

 has had any appreciable influence on color changes. 



6. Color changes of these species of Hyla seems largely under 

 nervous control. Various emotional and perhaps other psychical 

 factors appear to be dominant in the behavior above considered. 



As a final word I desire to express my obligations to the 

 Director and Staff of the Naples Zoological Station for cour- 

 tesies extended to me, and also to the Secretary of the Smith- 

 sonian Institution for the courtesy of an appointment to its 

 table at this renowned laboratory. 



