86 THE PLAY OF ANIMALS. 



opening and shutting doors." * Later, B. Sigismund 

 made use of the expression in his serviceable little 

 book,f and Preyer and Sikorski have established its use 

 in modern psychology. 



Since the babyhood of animals is so much shorter 

 than that of the human infant, it offers much less 

 material for psychological investigation, and, besides, 

 there is no Preyer for the animals. \ Still, we are not 

 entirely without material. 



"With the stretching of his limbs," say the Miil- 

 lers, " the young dog begins the first stage of his baby 

 play."* Puppies also begin very early to gnaw any 

 wooden object, as well as their own extremities, with 

 their little teeth, sharp as needles. Even the play with 

 their tails is at first purely experimental. Afterward 

 the chase instinct comes in, when the end seems to 

 vanish so mysteriously as they whirl. A dog that I once 

 owned was so small and weak that he always tumbled 

 over in attempting to bark. It was most ludicrous to 

 witness this ignominious ending to his hostile demon- 

 strations. A kitten, too, will play with its tail, and 

 exercise the claw-armed paws in seizing and holding. || 

 Scheitlin observed a young panther playing with its 

 own tail, A and Brehm relates how pumas at the age of 



* Jean Paul, Levana, 2d ed., vol. i, p. 164. 



f B. Sigismund, Kind und Welt, 1856, p. 73. 



X The thoroughgoing papers of Wesley Mills on the psychic 

 development of young animals were not known to the author when 

 this passage was written. They were published in 1894—1896. 

 [Prof. Lloyd Morgan's observations on young birds should also be 

 referred to ; cf. his Habit and Instinct, 1869.J 



* A. and K. Muller, Charactere aus der Thierwelt— 1. Der junge 

 Hund, Gartenlaube, 1867, p. 455. 



y As Wesley Mills observed on the twenty-ninth day. Loc. 

 cit., part ii. A Thierseelenkunde, ii, p. 155. 



