80 BRITISH BIRDS. 



bits of wood had been added. In half a dozen instances 

 the birds were seemingly content to preserve appear- 

 ances by merely placing or leaving two or three quite 

 useless stalks of bent around or across the nest. None 

 were as complete as the Common Tern's shown in the 

 tirst of my photographs (Fig. 1). It marks the highest 

 form of this type of nest. 



The second type was represented by three nests paved 

 with pebbles (Fig. 2). If the use of these pavements 



Fig. 3.— Arctic Tern's Nest in Sand. 



is to keep the eggs dry by raising them above the level 

 of soil liable to become damp, then we must deny the Terns 

 in question any sense of the meaning of their acts, for 

 their pavements were placed either on loose grit (Fig. 2) 

 or on loose sand, through both of which water would 

 rapidly sink. How unnecessary the pavement was is 

 shown by the third type, represented by two scraped 

 depressions in the bare sand. I kept the one shown in 

 Fig. 3 under close observation in foul weather and fair, 

 and had the pleasure of watching the owner (Fig. 4) hatch 

 out both her young successfully. 



