IQ2 



The Irish Naturalist. 



[September, 



either its feet or its beak for the purpose in question. I have 

 watched different colonies for some hours, with and without a 

 field glass, and have seen terns sitting in their nests, walking 

 round them, flying to and fro, but never actually in the act of 

 digging the hole. Perhaps this part of the procedure is 

 performed at night ? 



These facts led me to think that maybe the depression was 

 made by a process of what is commonly called by bird fanciers 

 "breasting." That is to say the bird presses its breast 

 against the sand, &c, and then commences to rotate back and 

 forwards through the arc of a circle, and through a vertical 

 axis passing from the dorsum or back of the bird to its ventral 

 aspect or breast. 





Figure; i. — Diagrammatic representation of a vertical section of the 

 nest of Sterna minuta in the first or unfinished stage.— C.J. P. 



Half natural size, 

 i. — Sloping wall of nest. 



2. — Lowest and narrowest part of depression. 

 3. — Sand lining nest. 

 4. — Shingles lying outside the nest. 

 5. — Sand under the surface of the shingles. 



Sparrows "dusting" themselves in the city streets afford 

 us a crude illustration of this performance. But the shape of 

 the depression minimises the truth of this theory. fl Breasting" 

 produces a cup shape and not the conical depression already 

 described. 



If we now neglect this method as a preliminary operation, 

 it remaixis to ask ourselves, are the feet or the beak brought 



