166 



SCIENCE 



[N. S. Vol. L. No. 1285 



■WINTERS OF 1917-1918 AND 1918-1919 COMPAKED 



The region west of the Rockies, which was 

 so warm in the winter of 1917-1918, was 

 generally unusually cold in December, 1918, 

 and in much of Utah, northern Arizona and 

 New Mexico, where the depth of snow was 

 great, in January, and much of February, 

 1919, as well. Throughout the rest of the 

 region, the past winter was not very unusual. 



Ohaeles F. Brooks ■ 

 Washington, D. C. 



SPECIAL ARTICLES 



A POSSIBLE CASE OF INSTINCTIVE BEHAVIOR 

 IN THE WHITE RAT 



Yerkes and Bloomfield^ demonstrated that 

 kittens instinctively kill mice but barely im- 

 plied the instinctive behavior of the mice 

 used. Berry2 states that mice do not show 

 any fear of cats. The following single ob- 

 servation seems to suggest that white rats do 

 instinctively fear cats. An entirely accidental 

 circumstance furnished a situation in which 

 a young cat came into the presence of several 

 cages of white rats. Although the cages were 

 some feet above the cat, its behavior was quite 

 comparable to that described by Terkes and 

 Bloomfield. In spite of the intensity of the 

 olfactory stimulus in the room, the reaction 

 of the cat did not take place until the visual 

 stimulus was presented.^ A periodic and al- 

 most spasmodic humping of the back and 

 bristling hair, but entire lack of vocal sounds. 



were the prominent features. Several minutes 

 produced no change in the situation save that 

 the cat, although making no eiiort at all to 

 reach the cages, became a little restless. 

 When, however, the cat was placed upon a 

 cage containing five white rats (female) about 

 six months old, their behavior was very 

 definite and specific. The cat responded to 

 the new situation — being high in the air with 

 unsafe footing — by paying no attention to the 

 rats but rather evidencing some fear. The 

 rats retreated to the rear of the cage uttering 

 peculiar whines, and showing other evidences 

 of fear. The cat was then removed and an 

 effort made to feed the rats. A specific vocal 

 sound made by the experimenter has always 

 been sufficient to call the rats to the front of 

 the cage where they are given small bits of 

 cheese. This stimulus has been so grafted 

 on to the feeding reactions that it invariably 

 awakens the, rats immediately from sleep, or 

 calls the female from a litter, and, subsequent 

 to the incident described, has repeatedly be- 

 come prepotent over states of fear produced in 

 other ways. Although over thirty-six hours 



1 "Do Kittens Instinctively Kill Mice?" Psychol. 

 Bull, 1910, 7, pp. 253-263. 



2 Berry, C. S., "An Experimental Study of Imi- 

 tation in Oats," J. of Camp. Nexirol. and Fsycliol., 

 1908, 18, pp. 1-25. (Quoted by Yerkes and Bloom- 

 field.) 



3 See Yerkes, et at, op. cit., p. 262. 



