POWER OF CALCULATION. 459 



even during summer ; while (3) there are other possible ex- 

 planations in the observance, for instance, of circumstances 

 that mark the proper times for going to or returning from 

 grass. 



A hedgehog on board ship crept into its box ' at dawn 

 and came out at dusk ' (Mrs. Mackellar). Here there 

 seemed to be a direct connection between its behaviour and 

 daylight. Houzeau mentions a hen that, with her chickens, 

 crossed a stream twice a day morning and evening to 

 reach a certain feeding ground. 



Periodicity of action, and the estimation of time, are not 

 confined, however, to the observance of certain hours, or of 

 morning, noon, and evening, or of given days in the week. Of 

 a certain foxhound Baker writes, ( I am convinced that he 

 knew the date of a track from its appearance ' that he could 

 determine its age. The ladajac reaps its grain and dries its 

 grain stores at the proper time (Houzeau). Butchers', bakers', 

 and newsmongers' dogs and horses pay periodical visits to 

 the residences of their masters' customers, without direction 

 (Watson). 



Many dogs especially have been described as knowing 

 the days of the week. But such cases almost invariably 

 resolve themselves into a distinction of Sunday from other 

 week-days, and occasionally of Saturday as a precursor of 

 Sunday. That these days are regarded as the first, 

 or sixth or seventh of each week there is no ground 

 for believing ; but the dog has no difficulty in recog- 

 nising Sunday at least as a holiday, marked by certain 

 things that man does and does not do. It is keenly 

 observant of the cessation from ordinary work, of the house- 

 hold hush of the Day of Eest, of the church-going and 

 all it implies such as its having to keep the house. To it 

 the day is what it is to so many children a pre-eminently 

 dull day in Scotland, where it does not get its usual walk or 

 run, and does not, unless in pastoral districts as explained 

 in another chapter accompany its master. 



A dog belonging to a certain grocer in Edinburgh 

 accompanies him regularly in his week-day walks, but never 

 attempts to go out with him on Sundays. The church bells, 



