434 JOHN B. WATSON 



is effected in the same act. Why the instinct of incubation needs 

 to have its "origin" accounted for any more than that of the 

 hundred other instincts birds possess is not clear. 



Craig (8, 9) gives the best description we have of the intimate 

 family life of the mourning dove. He describes the various 

 emotional states of the birds, such as those expressive of enmity, 

 fear, alarm, and gives their various calls and cries in musical 

 notation. The second part of the first paper (The Expressional 

 Life History) treats of the breeding habits of the mourning 

 dove. The breeding cycle of a pair of captive birds taken from 

 Professor Whitman's aviary is described in detail. 



His opportunity for making original observations upon the 

 passenger pigeon was more limited. The species is now appar- 

 ently extinct, and for this reason his rather brief notes upon the 

 life history of Ectopistes are of especial interest. This species 

 possessed characteristic voice, gesture and social life. It was 

 comparatively awkward upon the ground and was therefore 

 naturally less given to strutting and charging than other pigeons. 

 Its voice was strident and lacking in musical notes. While the 

 bird was quarrelsome, it was poorly equipped for fighting. Its 

 courting was characterized by great roughness. 



ORIENTATION 



Mammals. V. Maday (16) discusses the problem of orien- 

 tation in the horse. The origin of the impulse to home in this 

 animal is supposed by the author to have been carried over 

 from its wild ancestors. The Heimweh of the domestic horse 

 has its origin in the Wandertrieb of its wild progenitors. This 

 Heimweh is probably the most compelling impulse possessed by 

 the horse. 



Tests of homing were made by riding to distant points and 

 then releasing the reins, thus allowing the horse to return by 

 its own unaided efforts. The author tells us that he did not 

 direct the horse except when gross errors were made! Surely 

 the involuntary attitudes of the rider may have played a part 

 both in the successes and the failures of the animal! When 

 the horse reached the designated spot he was given the reins. 

 The animal remained still for from one to two minutes, then 

 started forward, then turned in the arc of a circle 10-15 m. in 

 diameter and for a short distance retraced the outgoing course, 



