110 CONTROLLED NATURAL SELECTION 
female, except perhaps the habit the male 
has of always rising first, when the pair is 
flushed. In this bird, pre-copulatory displays 
are by no means wanting. There yet remain 
to be accounted for, the Greylag Goose, Sand- 
martin, Tree Sparrow, and Tree-creeper ; some- 
thing might be said of each, but controversial 
and therefore doubtful facts would have to 
be utilised. 
Division II 
This division includes birds presenting 
bi-sexual attracting coloration for the pro- 
tection of their cryptically, or much _ less 
brilliantly coloured young. 
Many of these birds have a seasonal moult : 
in the winter, when they do not possess young, 
they don a cryptic dress. In some the change 
from juvenile to adult plumage is slow, and 
extends over several years: usually these 
full-grown but not maturely coloured birds 
do not breed, and therefore do not require 
attracting coloration for protection of young. 
Further, adult and immature birds often keep 
together, in companies, for several seasons, 
in which case the gradual change from juvenile 
to adult plumage would be a prolonged ad- 
