PUFFIN. 



95 



It had long been remarked, without any satisfactory ex- 

 planation being offered, that the old birds had much smaller 

 bills in summer than in winter. Owing to the investiga- 

 tions of Dr. Louis Bureau,* it is now established that our 

 Puffin sheds portions of its bill and the palpebral ornaments 

 in autumn, the horny frontal sheath scaling off in pieces 

 like plates of armour, and being accompanied by atrophy 

 and loss of colour. Analogous changes have subsequently 

 been observed in several of the North Pacific species of the 

 family. 



Varieties, more or less piebald, are not very uncommon, 

 and nearly perfect albinos are occasionally met with. 



* Bull. Soc. Zool. de France, 1877, pp. 377-399; of which an abridged 

 translation was published in 'The Zoologist,' 1878, p. 233. 



1^ \'\ 



