154 



K. S. LASHLBY 



probable, then, that when the greater weight and age of the 

 animals used in this experiment is taken into account, the group 

 corresponds rather to group B of the first experiment, which 

 also showed no tremor resulting from the drug and no super- 

 iority over the controls. 



The number of trials as a measure of the amount of practice 

 resulting in a given degree of efficiency is probably less depend- 

 able than the number of errors made during practice. The 

 distance traversed during training in excess of the shortest 

 path through the maze expresses the amount of practice fairly 

 accurately and the average excess distance has been computed 



TABLE 3 



A comparison of the distance traversed in excess of the true pathway during 

 learning of the maze by rats after injections of strychnine sulphate and of 



water 



for each of the groups trained. These averages are given in 

 table 3, and the individual records in figure 2. In the first 

 experiment there is practically no difference between the group 

 receiving 0.05 mgm. of strychnine and the control group. In 

 both experiments the groups receiving the larger dose of strych- 

 nine, 0.10 mgm., traversed a shorter distance in excess of the 

 true pathway than did the control groups. In the first experi- 

 ment this saving amounted to 41.2 per cent and in the second 

 experiment to 31.1 per cent. This difference between the 

 groups in the second experiment is greater than that revealed 

 by the number of trials. It is probable that the excess dis- 

 tance, or number of errors represents more accurately than the 



