LOCALIZATION OF SOUND IN THE WHITE RAT 293 



accurately; (4) older animals, including lions, tigers, panthers, 

 hyenas, bears, elephants, antelopes, zebras, sheep, angora goat, 

 various species of apes, land and water turtles, and 2 serpents, 

 all localized with varying degrees of accuracy. If the animal 

 oriented to the sound, Meyer presumed that it was endeavoring 

 to localize. Meyer has made a table cataloguing the reactions 

 of all these animals. No very definite conclusions were gained 

 because of the roughness of the experimentation. 



Johnson - and Szymanski 3 have each made a few tests on the 

 localization of sound by dogs. (The latter author has worked 

 with cats also.) Johnson found that his four dogs learned to 

 go to the source of sound after from 105 to 165 trials. Szyman- 

 ski's animals failed after from 21 to 30 (?) trials. (S. attributes 

 the failure to the small size of the experiment box which measured 

 9m. by 2.7 m. More probable causes are the small number of 

 trials given and the pernicious position habits that developed. 

 Johnson's box was differently constructed. He does not give 

 its dimensions in detail, but I judge it t© have been 24 ft. by 

 12 ft. The variations in size in the two boxes are thus negli- 

 gible.) In each experiment, the stimulus consisted of a sound 

 (a buzzer with J. and a bell with S.) which could be given in 

 either of two positions in front of and to either side of the sub- 

 ject. (4 m. away in S's work, about 10 ft. in J's study.) No 

 attempt was made in either case to increase the number of 

 positions in which the sound might appear; and in Johnson's 

 work little or no attempt was made to determine the cues used 

 in securing the positive results. 



In the present paper, I have been concerned primarily with 

 the following problems: (1) How accurately will white rats 

 localize sounds ? (2) To what extent does intensity (both 

 absolute and relative) determine the accuracy of response ? 

 The results throw additional light upon several supplementary 

 problems : sensitivity to tone and the nature of the learning pro- 

 cess. The study was made at the University of Texas during the 

 session of 1913-14, under the supervision of Prof. W. S. Hunter. 



Notes on Animals Used. Seven rats in all were used during 

 the experiment. Rats No. 4 and No. 6 (male) were obtained 



2 Johnson. H. M. Audition and Habit Formation in the Dog. Behav. Mon. 

 vol. 2, No. 3, 1913. pp. 46-51. 



3 Szvmanski, J. S. Lernversuche bei Hunden und Katzen. Pfluger's Arcliiv., 

 bd. 152, 1913. 



