338 



ROBERT M. YK11KKS 



then turned sharply to the right and passed directly into the 

 exit tube. In trials 22 to 30 it, instead, followed the right wall 

 of the stem, thus taking the shortest route to the exit tube 

 (figure 3). 



The route shown in figure 2 is typical of the early indirect 

 journeys; that of figure 3, of the later direct trips. 



As appears in table 1, the average time for the first 10 trips 

 was 163"; for the second 10, 103.5"; f° r tne third 10, 68.5". 



TABLE 1 

 Results op First Thirty Training Experiments with Worm No. 2 



Date Trial 



Oct. 12 1 



2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10 



Average of ten trials 



Oct. 16 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18 

 19 

 20 



Average of ten trials 



Oct. 17 21 



22 

 23 

 24 

 25 

 26 

 27 

 28 

 29 

 30 



Average of ten trials 



Contacts with 



Sandpaper Salt 







2 

 

 



3 



2 

 12 5 











3 1 



2.2 



1 



1 

 1 

 

 3 

 

 2 

 

 

 2 



.6 



1 





 







1 







1 





 

 



Time 



61" 



84" 



68" 



85" 

 146" 

 173" 

 480" 

 133" 

 152" 

 248" 



163" 



126" 



66" 



71" 



60" 

 159" 



87" 

 180" 



63" 

 114" 

 109" 



103.5" 



75" 

 109" 

 58" 

 46" 

 63" 

 61" 

 70" 

 56" 

 83" 

 64" 



68.5" 



These results strongly suggest to the student of animal be- 

 havior "tracking" or the directive influence of light. To the 



