22 COLEMAN E. GRIFFITH 



the back of the cage with all the indications of fear. About 

 fifteen minutes after the cat had been removed and efforts made 

 to dissipate the feline odor in the room, the mother of the very 

 young litter undertook in a hesitating and furtive way to return 

 to the nest some of the young which had been lustily crying. She 

 did so by seizing them in her teeth and depositing them one by 

 one in the nest in the forward part of the cage. She frequently 

 retreated to the rear of the cage, however, and assumed the old 

 posture. At the end of thirty-five minutes all the young had 

 been returned and the mother was beginning to resume her 

 usual behavior. It was nearly an hour before the mother of the 

 two-weeks-old litter had fully recovered. In a little over an 

 hour the two cages of adult individuals had quite recovered, their 

 normal feeding activities being interrupted now and then by 

 only a slight reversion to the old attitude. These observations 

 were further confirmed by four other cats and by repeated trials. 

 Now the writer has noticed that when young rats have not 

 been handled at all until they have just opened their eyes and 

 they are then picked up, they make violent efforts to escape. 

 There seems here to be an unlearned response to an unusual or 

 strange situation. The question arises, therefore, as to whether 

 or not the responses to the cat are not usual responses to any 

 new situation, the newness or the strangeness itself being the 

 essential point. The experimental procedure that has been 

 detailed in the foregoing was, therefore, repeated with two dogs, 

 several chemical substances, and other odors. The behavior 

 of the dogs was quite different from that of any of the cats. 

 There were frantic efforts to get at the rats, large amounts of 

 saliva being secreted and dropped about the cages and the floor. 

 The disturbance made was so great as to excite the rats, but 

 there was nothing qualitatively characteristic about this ex- 

 citement. The same sort of behavior on the part of the rats, 

 a running to and fro about the cage, etc., can be produced at 

 any tune by disturbing the nest and cage in a similar manner. 

 Moreover, there is no after-effect, the rats resuming their normal 

 activities as soon as the dog is removed. The use of a number 

 of chemical odors, including ether, alcohol, carbon disulphide, 



