24 G. V. HAMILTON 



jects presented one or more individuals whose records display 

 an abrupt appearance of C-reactions, their persistence for a 

 number of trials and their abrupt disappearance. It would 

 seem that the mammalian, both primate and infra-primate, has 

 a repertoire of more or less distinct reactive tendencies for 

 meeting situations which call for efforts to escape, and that 

 where a specifically adaptive adjustment is not learned, now 

 one, now another of these tendencies will come to expression. 

 From the standpoint of almost any of the behavior technologies 

 it is highly important to explore for the conditions that char- 

 acteristically set each of the various known tendencies in opera- 

 tion. This problem must remain an unsolved one so far as 

 the present studies are concerned, but I believe that it will be 

 found that C-reactions are not apt to occur under conditions 

 which are conducive to intensity of affective response. 



Some of the girls, particularly Girls 4, 7 and 10, tended to 

 alternate a first choice of alley No. 1 with a first choice of alley 

 No. 4 from trial to trial in starting the systematic (Type C) 

 search for the right alley. This largely accounts for the fact 

 that Girls 4 and 10 did not manifest a single A-reaction, although 

 a habit of displaying C-reactions is apt to yield as many " by 

 product " or incidental A-reactions as C-reactions. Another 

 factor which accounts for these two girls' failure to give any 

 A-reactions was this: whenever a given end alley proved to be 

 the right one it was tried first at the next trial, regardless of 

 the demands of the self -established alternating rule. Girl 7's 

 one A-reaction occurred during her sixtieth trial, when this 

 factor of recency failed to distract her from her habit of alternat- 

 ing her first choice of end alley with which to begin C-reactions. 



None of the animals displayed this trial-to-trial alternation of 

 first choice of end alley. Occasionally, however, a subject who 

 seemed to have fixed a habit of always trying first the alley at 

 a given end of the row would reverse his choice. E.g., all of 

 Monkey 16's C-reactions from his sixteenth to his fifty-sixth 

 trial were initiated by a first choice of alley No. 1, but on enter- 

 ing the apparatus for his fifty-seventh trial he tried No. 4 first, 

 and since No. 1 was the right alley for that trial he followed 

 this by entering alleys No. 3, 2 and 1 in the order given. During 

 the remainder of his series all of his-C reactions conformed to 

 the 4-3-2-1 order. 



