FARNE ISLANDS AND THEIR BIRDS 203 



of the chief causes I personally discovered to my 

 cost. In crevices, fissures, and hollows round and 

 about the nests, there is a dark green liquid covered 

 with a kind of thin crust or dust, which very much 

 resembles the surrounding rocks. This is, I think, 

 the chief cause of the unpleasant odour. While 



CORMORANTS 



I was focussing a nest I inadvertently stepped into 

 one of these horrible-smelling pools. I got out 

 quicker than I went in, but found that the mishap 

 had stirred up the liquid, thereby causing a stench 

 to arise which far exceeded all former experiences. 

 I did not at once attempt to clean my boot, but 

 while continuing my work I saw to my horror that 



