238 
ANIMALS IN MOTION. 
feathers is also distinctly seen in the pigeon, seriates 76 
and 77 ; the cockatoo during a second flight, series 80 ; 
the vulture, series 78 ; and it probably occurs in the flight 
of all birds, large or small. The dissection of a crane, 
made at the author’s request, proved the combined move¬ 
ment of the primary feathers to be under the control of 
the bird, and independent of any motion of the wing itself. 
Whether the act of soaring is accomplished by some, 
hitherto imperceptible, motion of the primary feathers may 
perhaps engage the attention of future investigators. 
