THE BIRDS OF NORTH KENT. 59 



these feathers have a very deep umber or almost black spot in 

 the centre of the web, leaving a pale margin all round. The 

 fluffy part at the base of the quill is whitish grey, but the margin 

 of the web surrounding the dark spot is a warm chestnut. As 

 far as my experience goes, there can be no possibility of confusing 

 the small feathers of the Mallard and the Shoveler, and I have 

 never yet found a nest of either of these species which had not 

 some of the breast contour feathers amongst the down. The 

 average size of these feathers corresponds to the size of the bird, 

 the Sheld-Duck's being largest, the Mallard's next, and the 

 Shoveler's least. From an examination of the down itself, 

 which, of course, forms the bulk of the covering of the nest, you 

 find that every particle of down consists of a minute abortive 

 quill, sometimes not much more than a scale of epidermis, from 

 which radiate numerous filaments equivalent perhaps to the 

 barbs of an ordinary feather. These are again branched through 

 their whole length with what may be called barbules, the latter 

 themselves being furnished with nodules, taking the place of the 

 ordinary barbicels and hooklets. As regards colouring, the 

 Sheld-Duck's down is a greyish white, with a touch of lavender. 

 The Mallard's and Shoveler's downs are both a deep umber-brown, 

 with a pale centre verging on dirty white. Normally the Shoveler's 

 is of a much darker brown than the Mallard's, but in the case of 

 a Mallard's nest, which I have described earlier (p. 51), the down 

 was much darker than that of any Shoveler's that I have seen. 

 Therefore, as regards colour, these two downs are very apt to be 

 confused. There is still, however, another means of differ- 

 entiating them. Each particle of down, if you lay it on a flat 

 surface, will, roughly speaking, form a fluffy sphere. That of 

 the Sheld-Duck is much the largest and most voluminous of the 

 three, and measures approximately 1*7 in. in diameter ; the 

 Mallard's comes next, measuring 1*3 in. ; and the Shoveler's is 

 the smallest, measuring 1*1 in. 



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