Chap. Viil. EXTERNAL DIFFERENCES. 295 



plumage as may occasionally be seen in our farm-yards, is a 

 fact worth notice. Nevertheless the climate of the Malayan 

 archipelago apparently tends to cause the duck to vary much, 

 for Zollinger, 12 speaking of the Penguin breed, says that in 

 Lombok " there is an unusual and very wonderful variety of 

 ducks." One Penguin drake which I kept alive differed from 

 those of which the skins were sent me from Lombok, in 

 having its breast and back partially coloured with chestnut- 

 brown, thus more closely resembling the Mallard. 



From these several facts, more especially from the drakes 

 of all the breeds having curled tail-feathers, and from certain 

 sub- varieties in each breed occasionally resembling in general 

 plumage the wild duck, we may conclude with confidence 

 that all the breeds are descended from A. boschas. 



I will now notice some of the peculiarities characteristic of the 

 several breeds. The eggs vary in colour; some common ducks 

 laying pale-greenish and others quite white eggs. The eggs which 

 are first laid during each season by the black Labrador duck, are 

 tinted black, as if rubbed with ink. A good observer assured me 

 that one year his ducks of this breed laid almost perfectly white 

 eggs. Another curious case shows wiiat singular variations some- 

 times occur and are inherited ; Mr. Hansell 13 relates that he had 

 a common duck wmich always laid eggs with the yolk of a dark- 

 brown colour like melted glue ; and the young ducks, hatched from 

 these eggs, laid the same kind of eggs, so that the breed had to be 

 destroyed. 



The Hook-billed duck is highly remarkable (see fig. of skull, 

 woodcut No. 39); and its peculiar beak has been inherited at 

 leust since the year 1676. This structure is evidently analogous 

 with that described in the Bagadotten carrier pigeon. Mr. Brent 14 

 says that, when Hook-billed ducks are crossed with common ducks, 

 " many young ones are produced with the upper mandible shorter 

 than the lower, which not unfrequently causes the death of the 

 bird." With ducks a tuft of feathers on the head is by no means a 

 rare occurrence ; namely, in the True-tufted breed, the Hook-billed, 

 the common farm-yard kind, and in a duck having no other pecu- 

 liarity which was sent to me from the Malayan archipelago. The 

 tuft is only so far interesting as it affects the skull, which is thus 

 rendered slightly more globular, and is perforated by numerous 

 apertures. Call ducks are remarkable from their extraordinary 



11 'Journal of the Indian Archi- (1849-1850), p. 2353. 

 pelago,' vol. v. p. 334. u 'Poultry Chronicle,' 1855, vol. 



15 'The Zoologist,' vols, vii., viii. hi. p. 512. 



