Allen, Association in the Gui)ica Pig. 303 



do not seem to understand the significance of the warning note 

 until they are three or four days old. Now that the guinea pigs 

 are quite thoroughly tamed, both the note of warning and ex- 

 pressions of fear are rarely observed. 



Other sounds uttered are series of shrill squeals and cries 

 indicative of hunger. When I enter the room, if it is near 

 feeding time, the little fellows remind me of their presence. 

 When I approach the basket of carrots, and particularh- when 

 the sound of cutting reaches their ears, their squeals are urgent 

 and vociferous. Each individual can be recognized by its voice, 

 as there is great individual variation. 



If general conversation is ever maintained amongst the 

 guinea pigs at their social gatherings, it consists only in an oc- 

 casional "ghrr-r-hr, " a sort of gutteral aspirate sound like a note 

 of perfect content with life. There is a characteristic tone 

 uttered by the male to attract the attention of the female. This 

 is the "coycobaya," which is said to have furnished the South 

 American natives with their name for the animal (Cobaya. Span- 

 ish, Cuy or Coy). The female responds with a low, musical 

 "r-rerp-rerp.'' 



If the guinea pig is surprised, or if anything of doubtful 

 character attracts the attention of the whole group, a "burr-r" 

 is uttered, and there is instant quiet throughout the room. If 

 the experimenter keeps perfectly still the guinea pigs remain 

 noiseless for several minutes. If, on the other hand, the cus- 

 tomary laboratory occupations go on, confidence is restored 

 and they return to their gnawing or eating. 



Observations of the young would lead to the conclusion 

 that fear is not present at birth. No motor expression of fear 

 could be produced by moving objects, or by any noise, or by 

 touching, pushing or striking. The only reactions to sound 

 that seem to be indicative of fear are those produced by a shrill 

 whistle as described later. It must be remembered that labora- 

 tory conditions are unfavorable for the awakening of fear in 

 those animals whose only enemies are creatures of the grass 

 and copse. 



The hiding instincts of the guinea pigs remind us distinctly 



[II] 



