HABIT FORMATION IN THE DOG 17 



In another animal post mortem showed that only the lowest 

 turn of the cochlea, with the part of the organ of Corti arfd of 

 the ganglion cells contained in it, was destroyed. The parts 

 lying in the middle turn of the cochlea, however, were atro- 

 phied, and the vestibular apparatus was slightly damaged. This 

 animal, which had been trained to react only to Bi and C3 as 

 food-tones, and to spoken words, and from which previous to 

 this operation the other cochlea had been removed, had reacted 

 both to tone and to noise as had normal animals. 



From other animals, one cochlea having been removed, one 

 side of the remaining cochlea was also extirpated, leaving the 

 other side intact, and not injuring the vestibular apparatus. 

 These after the operation did not react to their food-tones until 

 helped. They had lost their "absolute" sensitivity to pitch, 

 says Kalischer, but could still be made to discriminate between 

 food-tones and "Gegentone," even if the difference was only 

 half a tone. In other animals in which the vestibular apparatus 

 was more or less injured by this operation, disturbances corres- 

 ponding to the degree of injury were observed. That is to say, 

 they could not be made to differentiate between tones lying 

 close together in pitch, but could differentiate between tones 

 lying farther apart. 



From these data Kalischer concludes that the theory of Helm- 

 holtz and others that the different parts of the cochlea and of 

 the basilar membrane act selectively as receptors of long or 

 short sound-waves, is untenable. Also, that the vestibular appa- 

 ratus possesses an auditory function, and is necessary for pitch- 

 discrimination. Further, that all clang -analysis takes place "in 

 the peripheral end-organs of the nervus acusticus." 



In an Anhang to this part of his report Kalischer says that 

 some of his dogs were brought to discriminate between tri- 

 chords as well as between simple tones; for instance, an animal 

 trained to react to e^ and to inhibit reaction to ebS would also 

 react to the chord c'e'g^ and inhibit reaction to the chords 

 c^eb'g', Cij^i ei^' g^\ d^ f# a\ etc. He further says that by the use 

 of a mouth harmonica he was able to demonstrate in experiments 

 conducted in the stable, that the ass also possesses sensitivity 

 to "absolute pitch.'" The total time required for this demon- 

 stration was about one and one-half weeks. 



