THE  ASSUMPTION  AND  CHANGES  OF  PLUMAGE  IN  BIRDS.  19 
Herring  Gull. — Larus  argentatus,  Brunn.  Lesser  black-backed  Gull. — Larus 
fuscus,  Id. 
The  change  of  colour  in  the  plumage  of  these  Gulls  commenced  about  the  14th  of 
February,  and  from  that  time  there  has  been  a  constant  change  of  colour  going  on  in 
the  feathers.    The  moulting  of  these  birds  does  not  appear  to  expedite  the  change  of 
colour.    The  new  feathers  have  much  the  same  hue  as  those  that  have  been  shed. 
^     Laughing  Gull.— Larus  ridibundus,  Linn. 
The  feathers  on  the  head  of  this  Gull  began  to  change  colour  from  white  to  black  on 
the  1 1th  of  March.  It  was  a  change  of  colour,  and  not  an  act  of  moulting ;  no  feather 
was  shed,  and  the  change  was  completed  in  four  or  five  days.  The  plumage  remained 
in  this  state  as  to  colour  till  the  19th  of  July,  a  period  of  eighteen  weeks  and  five  days, 
when  the  black  feathers  were  moulted,  and  the  new  feathers  came  white.  The  autumn 
moult  lasted  seven  weeks. 
D  2 
