72 



DAY AND BENTLEY 



TABLE IV 

 After Interval in Watch Glass 



TABLE V 

 Paramecium C. after Second Interval (30 Min.) in Watch Glass 



Phase 1 



No. of 



reversals 



Ave. No. 

 of trials 



6.0 



Phase 2 



No. of 



reversals 



19 



Ave. No. 



of trials 



1.05 



The curves and tables suggest a marked difference in the 

 history of the first and of subsequent tests. The curves for 

 the first test are much like the " trial-and -error " curves for 

 mammalian forms. They begin high, drop quickly if irregu- 

 larly, pass through a middle, saw-tooth phase, then drop to 

 a low level with small fluctuation (cf. Table I). In the second 

 test, the curve usually starts lower, drops, shows a reduction 

 or absence of the second phase, and ends in a low flat line nearly 

 parallel to the axis of abscissas.^ 



* M and Q are less satisfactory than the others. In the second test, these indi- 

 viduals became very inactive and soon ceased to move. C is perhaps typical; 

 for it maintained active movements nearly the whole time. 



