26 



STELLA BURNHAM VINCENT 



ing in spite of his deformity. The females were slow and Baby- 

 as might have been expected was the quickest of the lot. Some 

 of the rats abandoned the edge of the walk in the later trials but 

 others followed it to the very last time. When they came to 

 the entrance to a cul de sac they crossed over but continued, 

 on the other side of the alley, to go along the edge which they 

 had been following. 





/i 





Fig. 7 — Fifth trial of rat " 5 " — vibrissae cut on the left side. 



The detailed path of some of these i-uns has been mapped and 

 appears in figs. 4, 5, 6 and 7 the learning curves in figs. 8 and 9. 



Summary of Experiment IV. 



Five rats in maze — vibrissae cut on the right side. 



Average errors in the first twenty-five trials 41. 



Average errors in the first trial 44 



Average time of 'earning (trial) 10.6 



Average time of the last ten trials in learning 36.6 sec. 



Average t me of the last of these trials 18. 



Slips and falls in the first twenty-five trials (avg.) 2.8 



