19 



food, and aa many as sixteen sheets of paper have been neces- 

 sary to trace the pathway during a single trial. At the moment 

 of entrance into the food box (F.B.), the watoh was stopped, 

 the time noted, and the animal at once removed. This constitut- 

 ed one trip or one trial. The rat was imn.ediately introduced 

 for a second trial, in whieli the same procedure was followed 

 excejt that on reaching the food it was allowed to eat for 

 five minutes before being removed. Tlie feeding j.eriod was care- 

 fully timed with the purpose of keeping the hunger stimulus as 

 uniform as possible. A short ration of grain was throv.n into 

 the living cage, and no more food was allowed luitil the next 

 day's work. Basset had given grain only twice a week, and 

 noted in consequence a disturbance in behavior on the day fol- 

 lowing that on which grain was given. Ulrich^ fed his animals 

 in the cage after work, which may account for their slowness 

 in learning the maze as compared with the rate used in this 

 problem. 



Two trials were given each day until the problen was 

 learned, i.e., until in six trips made on three consecutive 

 days no error was made from start to finish. In boti. Basset's 

 and Ulrich's work, a time norm was set, and although no useless 



1. Bassett, G. C, Eabit Formation, Scc, Behavior Ponograph 2, 

 (1914), Ho. 4. 



2. Ulrich, V/ork unpublished. 



