AVES ANATID^.. 495 



sufficient power to raise the body, serve only to propel it along rather 

 than through the water, and are used like the paddles of a steam-vessel. 

 Aided by these and its strong broad-webbed feet, it moves with astonish- 

 ing velocity. It would not be an exaggeration to state its speed at from 

 twelve to fifteen miles an hour. The peculiar form of the wing, and the 

 short rigid feathers which cover it, together with the power this bird pos- 

 sesses of remaining a considerable time under water, constitute a striking 

 link between the genera Anas and Apfcuodytcs. It has been noticed by 

 many former navigators. The largest we found measured forty inches 

 from the extremity of the bill to that of the tail, and weighed thirteen 

 pounds ; but Captain Cook mentions, in his voyage, that the weight of 

 one was twenty-nine pounds. It is very difficult to kill them, on account 

 of their wariness and the thick coat of feathers, which is impenetrable by 

 anything smaller than swan shot. The flavour of their flesh is so strong 

 and fishy, that at first we killed them solely for specimens. Five or six 

 months, however, on salt provisions taught many to think such food 

 palatable, and the seaman never lost an opportunity of eating them. I 

 have preferred these ducks to salt beef, as a preventive against scurvy, 

 rather than from liking their taste.' King also distinguished two species 

 of steamer-duck, whereof one (the Anas byachyptera of Latham, Micvop- 

 terus brachypterus of Ouoy and Gaimard), was entirely incapable of flight ; 

 and the other, which he denominated by the specific name of PatacJionicns, 

 was stated to be smaller in size than the Brachypterits, possessed of 

 volant powers, and differing also in other points relating to plumage. 

 Mr. Darwin, who describes the bird as he saw it at the Falklands, men- 

 tions but one species, the original Anas brachypteya, which he describes 

 as incapable of flight. 



"I will now pass on to offer a few remarks on the bird, as derived from 

 numerous observations which I had opportunity of making with regard to 

 it at the Falkland Islands, in the Strait of Magellan, and on the west 

 coast of Patagonia. At the outset I may state that, though undoubtedly 

 some steamer-ducks fly, and others appear to be either wholly incapable 

 of flight, or do not make use of their faculties in this respect, it is, neverthe- 

 less, my belief that there is only one species of the genus Micropterus, and 

 that the variations in size, capability of flight, and colouring of plumage, 

 are chiefly dependent on the age of the birds. Secondly, it is my opinion 

 that it is the young birds that can fly, and that the power of flight or the 



