344 'Journal of Comparative Neurology and Psychology. 



attitude toward certain persons, usually strangers. I first noticed 

 it one day when an expressman called to leave a package. He 

 entered without noticing her and when he turned to leave she was 

 on a cage which he must pass in going to the door. Her mouth 

 was oi)en, her teeth exposed, and her body drawn into a crouching 

 attitude as if she were about to spring. I intervened, while the 

 man left, for fear she might bite or scratch him. A day or two 

 later she behaved in the same way toward the laboratory machinist, 

 who came in to do some work. As he went toward the door, her 

 fury increased like that of a dog after a retreating enemy. I began 

 to suspect there was more of bluff than fight in her behavior and 

 my suspicions were fully justified a few days later. Experiments 

 were over for the day and ISTo. 1 was having her freedom about the 

 room to the delight of the several persons present. A stranger 

 entered the room. She was at the opposite end and on top of a 

 six-foot cage when he entered. She immediately prepared for war 

 and her scolding and threatening began. She advanced toward him 

 along the top of the cage by short leaps, which grew shorter as she 

 neared him. Her scolding increased, her hair became erect and 

 her wide-open mouth showed her keen teeth as if she were ready 

 to bite. Suddenly she leaped from the cage toward him (most 

 men would have dodged or struck, but this man did neither) and 

 she landed plump upon his chest. Instantly her harsh cries became 

 more like the purr of a cat, and her hand found its way to his 

 jewelled tie pin and on up to his moustache. She was not angry. 



!No. 2 never assumed the bluffing attitude. He showed, however, 

 more ingenuity in learning to do things. During his whole life in 

 Cambridge and also in ISTew York he refused to be petted, and 

 when caught was in . great fright. This fear often distracted his 

 attention from working at problems. He worked by spurts, glanc- 

 ing at persons in the room and then making a vigorous thrust or 

 pull at the mechanism. It was only by maintaining the most rigid 

 quiet in a room that I could induce ITo. 2 to give continuous atten- 

 tion to a problem. Despite this fact, however, he learned to get 

 food in devious ways much more quickly than !N"o. 1, whose familiar- 

 ity with human beings had possibly led her to depend on them for 

 her food. 



