This  the  observer  was  enabled  to  distinguish,  in  consequence
of  the  dark  colour  of  the  fish  contrasting  with  the  lighter
colour  of  its  mouth  when  opened.  The  vibration  continued
for  a  second  or  two,  when  the  male  left  the  female  and
retired  below."

It  has  been  shown  that  whilst  the  female  is  spawning,  the
male  is  stationed  some  few  feet  in  her  rear.  Again,  at  a
respectful  distance  behind  him — say  twelve  or  fifteen  feet,  but
still  in  a  direct  line  with  the  female^ — a  lot  of  trout,  sea-trout,
and  other  fish,  are  always  posted,  in  readiness  to  pounce
on  the  eggs,  when  the  female  starts  them  adrift  with  her
tail.  On  the  appearance  of  the  several  clouds  of  dirt,  it  is
amusing  to  see  them  all  scurrying  into  the  thick  of  it,  and
following  the  ova  down  the  stream.
It  has  never  been  observed  that  the  female  has  a  liking  for
one  male  more  than  another;  but  it  has  been  repeatedly  noticed
that  some  one  male  in  particular  occupies  the  same  spot.
At  some  little  distance  to  the  right  and  left  of  this  male,
two  or  three  other  males  are  usually  to  be  seen,  and  much
of  his  time  is  occupied  in  keeping  these  interlopers  at  a

VOL.    I.  H


98


REPELLING    INTRUDERS.
distance.  His  charges  against  them  are  most  vigorous  and
determined,  and  so  frequent  that  he  is  seldom  stationary  for
a  minute  together.  This  almost  incessant  motion  of  the  male
seems  a  special  provision  of  natiu-e ;  for  were  he  to  remain
still,  only  that  portion  of  the  ova  which  passes  over  him  would
be  impregnated,  whereas  by  moving  so  much  about,  his  milt
becomes  distributed,  in  a  manner,  over  the  whole  stream.
PROCESS  OF  SPAWNING.
