POWER OF CALCULATION. 461 



fourteenth day, but simply by observing the earliest prepa- 

 rations for its bath. Its periodicity of action may have been 

 determined simply by periodicity of action in its master or 

 mistress. 



Dogs distinguish certain other days of a season such as 

 Christmas, assize or cattle-killing days, hunting days (ap- 

 pointed for the * meets' of hounds), and in general all holi- 

 days or other days marked by unusual events by any depar- 

 ture from the routine of daily life. In all these cases they 

 probably observe man's preparations for the business or 

 sports of the day, more especially perhaps his change of dress. 

 They readily distinguish Sunday clothes from a hunting cos- 

 tume, and both from the ordinary working day habiliments: 

 they quite understand the object of such changes of dress, 

 and their association of ideas enables them to connect even- 

 ing in-door full dress with balls or parties, or the scarlet coat 

 and top-boots with the hunt, as well as with the fact that, 

 when dressed in a particular way, and when going to a par- 

 ticular place, they may, or must not accompany their masters. 

 Their behaviour is in accordance with their logical inferences 

 from observation : they exhibit indifference or sulkiness in 

 one case, joy, friskiness, vivacity in the other. 



The power of the dog, horse, mule, donkey, elephant and 

 other animals to count or reckon, in some way, intervals of 

 time, and the exactness of their reckoning are illustrated 

 in many other ways : for instance, by their punctuality and 

 regularity in betaking themselves to, and relieving each other 

 from, duty in taking turn and turn about at work. 



In various ways, certain animals show that they can 

 correctly calculate or estimate space or distance, including 

 height. The horse, for instance, in the steeple chase or 

 hurdle race, calculates hurriedly the height of the fence he is 

 about to leap ; the dog does the same when he is invited to 

 jump through a hoop for a bit of bread ; the lion and other 

 predatory carnivora estimate both height and distance in 

 their contemplated spring upon their prey. Certain fish are 

 called shooting or archer fish from their precision of aim in 

 bringing down flies on the wing, by squirting at them drops 

 of water, the nicest calculation of the intervening space, as 



