CHAP. XIII. ] LOWER ANIMALS. 213 



extremely limited in the scope of their apprehension. Its 

 touch being thus defective, what is there then in the dog 

 to play second to sight which as leader needs support, 

 were it only because there is not always light to see with ? 

 Smell, I cannot but think, seeing that, whilst the organ is 

 incontestably acute, it has the great advantage over the 

 tactile surface of the lips, of receiving impressions from 

 things already at a distance. If we only suppose what 

 the facts make very likely that the dog's smell is acute 

 enough to have some sensation from all bodies without 

 exception, nothing more is wanting to enable a psychologist 

 to understand that the dog's world may be, in the main, a 

 world of sights and smells continuous in space." 



Horses, also, would seem to have a similarly acute sense 

 of Smell, and an interesting fact is cited by Mr. Darwin 

 which apparently illustrates this point. He says,* 



" Many years ago I was on a mail-coach, and as soon as we 

 came to a public-house, the coachman pulled up for a fr.iotion of a 

 second. He did so when he came to a second public-house, and I 

 then asked him the reason. He pointed to the off-hand wheeler, 

 and said that she had been long completely blind, and she would 

 stop at every place in the road at which she had before stopped. 

 He had found by experience that less time was wasted by pulling 

 up his team than by trying to drive her past the place, for she was 

 contented with a momentary stop. After this I watched her, and 

 it was evident she knew exactly, before the coachman began to 

 pull up the other horses, every public-house on the road, for she 

 had, at some time, stopped at all. I think there can be little doubt 

 that this mare recognized all these houses by her sense of smell." 



It seems pretty certain, however, that many of the 

 actions of lower animals, in finding their way to distant 

 places, cannot be explained by reference to any of the 

 senses, either singly or in combination, which we have as 

 yet considered. How, for instance, is the Dog, the Cut, 

 * -NTot.nrfl " March 13. 1873. p. 360. 



