168 



OTTO C. GLASER 



Two facts of considerable interest are to be read in these trac- 

 ings. In series B, C, D, and E, the pathways are without excep- 

 tion dextral; in series E, on the other hand, all the turns made are 

 sinistral. A directive factor seems to be operative, but analysis 

 shows that it may not be simple. A considerable number of tests 

 was made with blindfolded animals, and with young whose eyes 

 were not yet open. The results in general indicate that certain 

 individuals have a natural disposition to turn to the right, rather 

 than the left, in swimming, whereas in others the reverse tendency 

 is equally marked. I have made no experiments to determine 

 whether this tendency is due to differences in the semi-circular 



TRIALS 



TIME 



Fig. 2. Graphic representation of six sets of trials made by six individuals. 

 The squares represent the tank, the incomplete corner, the open exit. Above the 

 first series of records are figures indicating the number of each trial, whereas 

 beneath the squares are the time records made in traversing the pathway indicated 

 within each square. In every case the animal started from the central dot. 



