172 MISCELLANEOUS OBJECTIONS TO THE [CHAP. VIL 



From the highly developed structure of the shoveller's beak we 

 may proceed (as I have learnt from information and specimens 

 sent to me by Mr. Salvin), without any great break, as far as 

 fitness for sifting is concerned, through the beak of the Merganetta 

 armata, and in some respects through that of the Aix sponsa, to 

 the beak of the common duck. In this latter species, the lamellae 

 are much coarser than in the shoveller, and are firmly attached to 

 the sides of the mandible ; they are only about 50 in number on 

 each side, and do not project at all beneath the margin. They are 

 square-topped, and are edged with translucent hardish tissue, as if 

 for crushing food. The edges of the lower mandible are crossed 

 by numerous fine ridges, which project very little. Although the 

 beak is thus very inferior as a sifter to that of the shoveller, yet 

 this bird, as every one knows, constantly uses it for this purpose. 

 There are other species, as I hear from Mr. Salvin, in which the 

 lamellae are considerably less developed than in the common 

 duck ; but I do not know whether they use their beaks for sifting 

 the water. 



Turning to another group of the same family. In the Egyptian 

 goose (Chenalopex) the beak closely resembles that of the common 

 duck ; but the lamellae are not so numerous, nor so distinct from 

 each other, nor do they project so much inwards ; yet this goose, 

 as I am informed by Mr. E. Bartlett, "uses its bill like a duck by 

 throwing the waters out at the corners." Its chief food, however, 

 is grass, which it crops like the common goose. In this latter bird, 

 the lamellae of the upper mandible are much coarser than in the 

 common duck, almost confluent, about 27 in number on each side, 

 and terminating upwards in teeth-like knobs. The palate is also 

 covered with hard rounded knobs. The edges of the lower 

 mandible are serrated with teeth much more prominent, coarser, 

 and sharper than in the duck. The common goose does not sift 

 the water, but uses its beak exclusively for tearing or cutting 

 herbage, for which purpose it is so well fitted, that it can crop 

 grass closer than almost any other animal. There are othe 

 species of geese, as I hear from Mr. Bartlett, in which the lamella 

 are less developed than in the common goose. 



We thus see that a member of the duck family, with a beat 

 constructed like that of the common goose and adapted solely foi 

 grazing, or even a member with a beak having less well-developec 

 lamellae, might be converted by small changes into a species lik 

 the Egyptian goose, this into one like the common duck, and 

 lastly, into one like the shoveller, provided with a beak almos 

 exclusively adapted for sifting the water ; for this bird couk 

 hardly use any part of its beak, except the hooked tip, for seizing 

 or tearing solid food. The beak of a goose, as I may add, mighi 

 also be converted by small changes into one provided with 



