British Diving Ducks 
3 
he argues that a feather is so much dead structure. On the other hand, he has admitted to 
me that his microscope is not a very powerful one, and that it is possible there might be 
some mode of transference too small for the eye of any glass, except one of extraordinary 
power, to detect. 
With regard to the actual colour and pattern changes, not necessarily due to a fresh 
rise of colour, which I have asserted do take place, I am glad to have the support of several 
field and scientific naturalists whose observations and opinions I most value because they 
are each and all Duck specialists, and they have sent me many (unsolicited) letters in cor- 
roboration of my views. Mr. Wormald, the Honourable Gerald Legge, Lord William Percy, 
Lewis Bonhote, Mr. E. Lehn Schioler, are all quite satisfied on this point. I only quote 
one letter from the last-named ornithologist, who has devoted a life to the study of Ducks. 
•'My collection of those ducks (I have 200 M. penelope and 300 to 400 Anas boschas) is especially 
rich in eclipse plumages, and, as you say, this plumage shows wonderful colour changes, I, for my part, 
have no doubt but your views are correct, but how are we to understand the meaning of these changes ? 
I can quite well understand those who hold the opinion that, once full grown, a feather cannot change, 
but at the same time it seems to me a weak point to wish to prove that which cannot take place when it 
does do so. 
" I, for my part, believe that colour changes in feathers are to a large extent due to wear of a part or 
of the whole feather. Not only the tops but the surfaces are removed to give place to a new colour and 
pattern. Many diverse birds such as Redpolls, Dunlins, &c.^ do this, but certain it is that colour and 
pattern change do take place, and it is impossible to any one who has accustomed his eye to look upon 
those things to deny the fact, if a man takes the trouble to skin his specimens himself." 
This "wearing" of the whole surface so as to disclose the underlying new pattern 
and colour of say the spotted feathers or the cheeks of the Mallard Drake, which appear 
just before they are shed in late June, is one form of colour change. But it does not 
explain the remarkable "rise" of colour that comes with the curly feathers of the tail in 
August. These feathers (which are only renewed once in the year) come in rich brown 
with a black centre. So they remain for a short period, but later in September, as they 
elongate and curl, they begin to turn black, until by the end of the month they are jet-black. 
A rise of colour must therefore be in course of movement the whole period as the feather 
elongates, and must prove that there is a means of transmission either through veins or 
figment cells of infinitesimal size. Any naturalist can prove these two points by keeping 
a Mallard Drake or two alive and examining them daily from June to September, but 
so far my opponents have remained blind to these facts. 
It has always seemed to me that Ducks are divided into too many genera, and that 
several which only show trifling differences of character from those nearest akin are quite 
superfluous. I have therefore discarded such as Netta and Fuligula, bringing them into 
Nyroca, whilst Histrionicus and Harelda seem naturally to come within the scope of 
Clangula. 
Most of the young of Diving Ducks are born between the 28th of June and the 
8th of July, so that I have merely suggested July ist as the birth date of all 
species. This will give the reader examining the plates a definite basis on which to 
reckon the ages of the Ducks, whilst at the same time he must not imagine that I assert 
it as the exact date of birth of each individual bird. 
^ With this I quite agree. — J. G. M. 
