472 
Mr. J. Lewis Bonliote on Moult 
or early summer, representing individuals of a different age, 
will often show a nearly complete series of intergrades 
between the two styles of plumage, and there will, of course, 
be no signs of a moult.” 
I understand from this that Mr. Stone only recognizes 
intergrades on different individuals ; but if he were to study 
the Limicolse, which avowedly he has not done, the inter¬ 
grades would be found on the same individual. If, further¬ 
more, he would extend his observations to birds in con¬ 
finement, he would notice that the intergrades on any one 
individual do not remain constant, but that, “ although there 
were no signs of moult,” the intergrades would gradually 
give place, until the bird had assumed its full and complete 
plumage. 
There is no need to lay down a hard-and-fast law for all 
kinds of birds. In the Corncrake, for instance, there can be 
no change of pigment, since blue is not a pigment-colour. 
In the Linnets and Redpolls, although the change is from 
brown to red, no further pigment is introduced when once 
the feather is formed. The evidence on this point is as 
follows :—In confinement, through some cause as yet un¬ 
known, birds of this genus become yellow instead of red 
in their full dress. If a bird be taken wild in autumn in 
its brown plumage, it will become red the following spring ; 
on the other hand, if it should be taken in July, before 
moulting, it will become yellow in the following spring. 
This shows that in this case the red pigment is probably 
deposited in the feather when formed in the autumn. 
To sum up briefly, it appears, so far as we are at present 
able to judge,— 
I. That in some cases, e. g. Crex and Colymbus, a moult 
takes place entirely independent of colour-change. 
IT. That it does not follow that because a bird is moulting 
a colour-change in individual feathers, be they old or 
new, is thereby excluded. 
III. That in the same bird, and in the same feather-tract, 
a different plumage may be assumed, partly by moulting, 
and partly by a colour-change in the old feathers which 
are not cast. 
