124 MENTAL EVOLUTION IN ANIMALS. 



disturbed, and associating the sound of a bell with the arrival 

 of food.* 



Batrachians and Eeptiles are able to remember localities, 

 and also to identify persons.f The annual migration of 

 Turtles further proves the duration of memory for at least a 

 year. 



In Birds the power of memory has advanced considerably 

 beyond that of remembering, as in the case of the swallow, 

 the precise locality of their nests from season to season, and 

 even beyond that of identifying persons from year to year.J 

 For the facts which I have previously detailed at length 

 touching the acquisition by talking birds of tones, words, and 

 phrases, show not only an exceedingly high development of 

 the powers of special association, but even the power of 

 genuine recollection to the extent of knowing that there is a 

 missing link in the train of a previously formed association, 

 and of purposely endeavouring to recover it. Quotations 

 from Dr. Wilks, Mr. Venn, and Mr. Walter Pollock were also 

 given, in order to show from direct and careful observation 

 that the process of forming special associations is in such 

 cases identical with that which occurs in man.§ 



Among Mammals the highest development of memory is 

 presented by the Horse, Dog, and Elephant. Thus there is 

 unexceptionable evidence of a horse remembering a road and 

 a stable after an interval of eight years ;|| of a dog remem- 

 bering the sound of his master's voice after an interval of five 

 years,ir and the sound of a clinking collar after an interval of 

 three years ;1 and of an elephant remembering his keeper 

 after having run wild for an interval of fifteen years.** It is 

 probable, also, that if observations were made, the memory of 

 Monkeys would be found to be very retentive, as it certainly 

 is most minute, and largely assisted by the intentional efforts 

 of the animals themselves. ft 



* See Animal Intelligence, pp. 248-51. f Ibid., pp. 254-62. 



X Ibid., p. 266. § For all these facts, see ihid., pp. 266-70. 



II Ibid., p. 330. IT Ibid., p. 438. ** Ihid., p. 387. 



ft Ibid., pp. 485-98. 



