v A Chapter on Wagtails 119 



and even of self-satisfaction, as they trip along, 

 unaware that they are observed, by the water's edge ; 

 with no lack of food, with the pleasant noise of the 

 water ever in their ears, and with those long tails of 

 theirs perpetually moving up and down, as if in 

 rhythm with the water. It is worth noting that the 

 motion of these tails is not exactly that which we 

 have observed in the other two species ; it is not 

 so purely a tail-motion, and it is less rapid and more 

 regular. It is a motion of the whole body from the 

 breast tailwards ; it is only the great length of the 

 feathers that gives it the appearance of belonging to 

 the tail only. The verb to wag is utterly inapplic- 

 able to it, nor can I think of any word which will 

 exactly express it. One other bird that haunts our 

 British streams has the very same movement of the 

 whole body, and this is one which has but little tail 

 the Common Sandpiper. 



Before I leave these tails I have yet a few words 

 to say about them. In this scientific age, when 

 questions beginning with why are always being 

 asked, if seldom finally answered, I might feel it a 

 duty to the Wagtails to ask the reason of their tail- 

 motions. I do not indeed promise to explain them, 

 not at least with the easy conviction of a certain 

 popular writer, who (though it is but lately that he 

 learnt the difference between the Gray and the 

 Yellow Wagtails) assures us boldly that the object 



