46 A. M. REESE 



8. The reaction to green light is the same as to the red, but 

 less marked. 



9. The reaction to blue light is the same, but still less marked. 



10. A small spot of white light from a micro-electric torch 

 produced no effect when thrown upon various parts of the 

 animal's body. 



11. The animals responded promptly to a beam of sunlight 

 thrown on various parts of the body, either from above or below, 

 by a small mirror, though if the mirror threw a beam of 5 sq. 

 mm. or less there was little or no response. 



REFERENCES 



1. Pearse, A. S. The Reactions of Amphibians to Light. Proc. Amer. Acad. 



1910. Arts and Sc, 45, pp. 162-206. 



2. Reese, A. M. Observations on the Reactions of Cryptobranchus and Nec- 



1906. turus to Light and Heat. Biol. Bull., 11, pp. 93-99. 



3. Sayle, Mary Honora. The Reactions of Necturus to Stimuli Received Through 



1916. the Skin. Jour. Animal Behav., 6, pp. 81-102. 



ADDENDUM 



As a check upon the preceding laboratory experiments, the 

 following experiments were tried upon a number of newts of 

 the same species, under as near natural conditions as could be 

 obtained. The work was done, during the latter part of August, 

 in a small, fresh-water pond, about two miles from the labora- 

 tory at Woods Hole, Mass. 



Twenty-eight animals were obtained by sweeping a dip net 

 through the grass of this shallow pond. They were caught 

 during the morning, and were confined until night, and during 

 intervals between experiments, in a 12 in. x 12 in. floating live- 

 box, with wire top and bottom, which was partly filled with 

 grass and dirt from the pond. 



During experimentation they were confined in a cage 1 ft. x 

 2 ft. in area, 6 inches deep, and open above, made of one-quarter 

 inch wire netting. This cage was sunk about 5 inches into the 

 water so that it was surrounded by the grass of the pond. A 

 few of the animals escaped, during the experiments, by climbing 

 out of the cage. 



Only sunlight and artificial white light were used, the latter 

 being supplied by a miner's acetylene lamp with a reflector; 

 this lamp gave a fairly brilliant though rather variable light, 

 but its candle-power was not determined. 



