BIRDS IN THE GREENWOODS 229 



cases preceded — the body. Changes of structure, 

 too, if slight, are not easy to see, and as soon as 

 they become observable the varying animal is dubbed 

 another species, or, at least, a variety of the old 

 one, so that one is not allowed, as it were, to 

 see the actual passage from form to form ; — one 

 is always either at one end of the bridge or the 

 other end. But changed habits may be marked in 

 transitu, and there is hardly, perhaps, a bird or a 

 beast which, if closely watched, will not be seen to 

 act sometimes in a manner which, if persisted in to 

 the neglect of its more usual circle of activities, would 

 make it, in effect, a new being, though dressed in an 

 old suit of clothes. Thus, in such a bird as the robin, 

 which is associated — and rightly — in the popular 

 mind with the cottage, the little rustic garden, and 

 with woodlands wild — such scenes and surroundings, 

 in fact, as are represented, or used to be, on Christmas 

 cards — one may get a hint of some future little red- 

 breasted, water-loving bird, at iirst no more aquatic 

 than the water-wagtail, but becoming, perhaps, as 

 time goes on, as accomplished a diver and dinger 

 to stones at the bottom of running streams as is the 

 water-ouzel — a bird as to which, Darwin says, "the 

 acutest observer by examining its dead body would 

 never have suspected its sub-aquatic habits." 



To illustrate this, I take from my notes the follow- 

 ing : — " A robin " — it is in December — " flies on to 

 the trunk of a fallen tree spanning the little stream, 

 from thence on to some weedy scum lying against 

 it on the water, from which he picks something off 

 and returns again to the trunk. Two or three times 

 again he flies down and hops about . on the weeds, 



