THE PUFFIN". 303 



red, with four oblique furrows in the upper mandible, and 

 three in the under. The party-coloured and furrowed bill 

 are indications of maturity ; the young of the first year 

 have the whole bill smooth and bluish black ; the second 



The Puffin. 



year it grows larger, paler towards the tip, and has the 

 rudiment of one oblique groove ; in the third and succeeding 

 years, the bill acquires its full size and lustre. 



The bill of this bird is an instrument of great power, 

 with which it easily crushes the smaller Crustacea and 

 thinner-shelled mollusca, which are understood to form its 

 principal food. 



These birds are not only very numerous in the northern 

 latitudes ; but they range farther southward in their migra- 

 tion in quest of breeding-places than some others of the 

 arctic birds. They do not nestle in holes of the rocks so 

 much as in burrows in the sands and other soft and dry 



