THE WAGTAILS 245 



of vague surprise, perhaps, that the lining stage has been so quickly 

 reached, it proceeds in accordance with the undeniable fact. If I 

 remember rightly, however, there was much more than lining in what 

 had been added by a pair of pied-wagtails or rather by the female, 

 who alone builds to an old thrush's nest in my garden at Icklingham. 

 The bird seemed rather to have built its nest in the other, so that 

 before settling ourselves to explain this difficulty, if it be one, it would 

 be well to be more accurately informed as to how the facts really stand. 



Another interesting question in connection with the above 

 speculation is which of the two species the appropriating or the 

 dispossessed one would be the more likely to rear the false brood 

 or chick ? To me it does not appear impossible that the cuckoo was 

 first driven to parasitism by having its nest wrested from it that its 

 own eggs in its own nest made the first " dupes " of a robber pair. 



However or wherever the nest of the pied-, and, for the matter 

 of that, of the white-, grey-, blue-, etc., wagtail be made, it is an 

 extremely interesting sight to see the young birds fed in it. When 

 quite small, their four beaks which are anything but so all widely 

 distended and held up together, look very remarkable, and one may 

 even say beautiful. Outside, they are of a light, crude yellow very 

 bright but within, the hue is deeper, almost approaching to salmon, 

 or, at any rate, to some variety of that shade. Also, it has a peculiar 

 translucent quality, or rather appearance, and the general effect of 

 all four together is as of a pretty little piece of Venetian glass-work, 

 such as one sees at Salviati's indeed very much so. Into it that is 

 into all its four apertures is conveyed, at intervals, by both parents, 

 but very much more by the female, the stream of insect food. This 

 consists largely of flies or fly-like creatures, which are caught either 

 on the wing or as they alight upon leaf or grass-blade of any of the 

 varied vegetation clothing the ground. The bird then runs, with 

 extreme rapidity, from one point to another, picking them off, and 

 rarely seeming to miss one. With equal facility she catches them in 

 the air, and, from both sources of supply, has soon a little heap 



