CONCEALMENT. 67 



may be constructed and hidden, if we approach it 

 alone and creep in, many birds will desert their 

 eggs sooner than return ; they see us disappear 

 into that lump and henceforth that lump becomes 

 to them a source of burning fear, which is not 

 allayed until we have crept out and gone away, 

 if then. Some birds, particularly of the smaller 

 kinds, are possessed of shorter memories, or can 

 persuade themselves that they were mistaken 

 in what they saw, and ere long cautiously return, 

 but these are few in number. 



Fortunately it will nearly always suffice to de- 

 ceive them if two people approach the hide, 

 one entering it and, after he has been safely 

 fastened up, the other ostentatiously departing. 

 The vast majority of birds are thus completely 

 deceived, and if they have previously aban- 

 doned their fear of, and grown accustomed to, 

 the structure of the hide, will readily return 

 under the impression that it is empty. There 

 are a few, however, which seem to be able to 

 discriminate between the arrival of two and the 

 departure of one. I remember an old Carrion- 

 Crow which certainly only too fully appreci- 

 ated this difference, though she could not go 

 further and with certainty tell two from three. 

 To approach a nest each time three strong is rather 

 a tax on one's friends or pocket. An equally good 



