54 WILD TRAITS IN TAME ANIMALS. 



up, the wagging becomes more and more em- 

 phatic, until one after another the hounds begin 

 to whine and give tongue, and stream off in 

 Indian file along- the Hne of scent. When the 

 pack is at full cry upon a strong scent the 

 "sterns" cease to wave, but are carried aloft in 

 full view. 



The whole question of tail-wagging is a very 

 interesting one. All dogs wag their tails when 

 pleased, and the movement is generally under- 

 stood by their human associates as an intimation 

 that they are happy. But when we attempt to 

 discover the reason why pleasure should be 

 expressed in this way, the explanation appears 

 at first very difficult to reach. All physical 

 attributes of living beings are, upon the evolu- 

 tionary hypothesis, traceable to some actual 

 need, either past or present. The old and 

 delightfully conclusive dictum that things are 

 as they are because they are made so " in the 

 beginning," no longer can be put forward to 

 settle knotty problems in natural history. No 

 doubt, in many cases — as, for instance, when 

 we speculate on the primary origin of human 

 laughter — the mystery seems almost unfathom- 

 able. But this present helplessness onl)- results 



