160 ANIMAL INTELLIGENCE 



organism, somatic and psychic, is dependent on im- 

 pressions, ancestral, pre-natal, and post-natal. It is 

 simply impossible that it should be otherwise. How- 

 ever, in the more restricted sense of the word " memory," 

 a good instance is to be noted in the behaviour of the 

 puppy that was accidentally trodden upon by me. This 

 occurred on the 47th day, and up to the date of the 

 conclusion of the diary, on the 60th day, it was very 

 clear that he remembered this unpleasant event. 



Memory is very retentive in dogs, though there seem 

 to be, in this respect, as much individual difference as in 

 human beings. I had a greyhound that could not see 

 a cat on the street without giving chase ; and he would, 

 after many months, remember the identical tree up 

 which the cat climbed when he was in pursuit. This 

 is, moreover, a case of visual memory in all probability, 

 as it is not likely that the scent from the cat would 

 remain for six months. 



EECOGNITION. From several experiments recorded, as 

 the result of introducing other bitches into the same 

 compartment with the puppies, the reader may be able 

 to draw some conclusions. From the behaviour of the 

 puppies I conclude that, at the time of the later experi- 

 ments, the fact that they attempted to suck the 

 strangers is not evidence that they were mistaken for 

 the dam, but that they simply had such a desire to 

 suck that they were willing to accept what they could 

 get. They, in one instance, gave the clearest preference 

 for the dam, and at once, guided probably by sight 

 chiefly, for dogs' judgments are quickest by sight, 

 though often corroborated by smell. Smell is their 

 surest guide, and always called into use in doubtful 

 cases. See especially the record for the 36th day. Of 

 course, I witnessed evidence for my conclusion, which 

 in this, and other cases, it is not possible for me to fully 

 communicate by words 



