f  "  Popular  Lectures  on  Scientific  Subjects,"  Eng.  trans.,  1873,  pp.
219,  227,  269.  390.
502  TBE  DBBGEMf  OF  MAif.
exhibited  by  the  feathers  on  the  same  bird  do  not  at  all
necessarily  show  us  the  steps  passed  through  by  the  extinct
progenitors  of  the  species;  but  they  probably  give  us  the
clue  to  the  actual  steps,  and  they  at  last  prove  to  demon-
stration that  a  gradation  is  possible.  Bearing  in  mind  how
carefully  the  male  Argus  pheasant  displays  his  plumes
before  the  female,  as  well  as  the  many  facts  rendering  it
probable  that  female  birds  prefer  the  more  attractive  males,
no  one  who  admits  the  agency  of  sexual  selection  in  any
case  will  deny  that  a  simple  dark  spot  with  some  fulvous
shading  might  be  converted,  through  the  approximation
and  modification  of  two  adjoining  spots,  together  with
some  slight  increase  of  color,  into  one  of  the  so-called  ellip-
tic ornaments.  These  latter  ornaments  have  been  shown
to  many  persons,  and  all  have  admitted  that  they  are  beau-
tiful, some  thinking  them  even  more  so  than  the  ball-and-
socket  ocelli.  As  the  secondary  plumes  became  lengthened
through  sexual  selection,  and  as  the  elliptic  ornaments
increased  in  diameter,  their  colors  apparently  became  less
bright;  and  then  the  ornamentation  of  the  plumes  had  to
be  gained  by  an  improvement  in  the  pattern  and  shading ;
and  this  process  was  carried  on  until  the  wonderful  ball-
and-socket  ocelli  were  finally  developed.  Thus  we  can
understand — and  in  no  other  way  as  it  seems  to  me — the
present  condition  and  origin  of  the  ornaments  on  the
wing-feathers  of  the  Argus  pheasant.
