THE ADELIE PENGUIN. 51 



and safely rear its young within a few yards of its own most sacred nest. I have seen 

 the Adelie Penguin peck at and demolish its own egg which had a minute before been 

 removed for inspection and had been put back under it, resenting the intrusion of what it 

 evidently did not recognise as an egg at all. This, again, is no great sign of intelligence. 



Of its cleanliness there is nothing to be said but praise, for no bird on earth 

 could possibly be more strictly clean than the Adelie Penguin. Hunt as one might, no 

 parasite could be discovered amid the snowy feathers, nor any trace of dirt or adventi- 

 tious matter. Within, it has, in common with all other birds and beasts of the 

 Antarctic, abundant nematodes and quite a host of various forms of microbes, but 

 externally it is scrupulously clean. 



There cannot now, I think, be much doubt that the Adelie Penguin takes not one 

 year but two to reach maturity. It joins the breeding colony for the first time not at 

 the end of its first but of its second year. Appearing from the egg in the middle of 

 December, the colour of the little downy-coated nestlings is somewhat variable. 

 Two are almost always hatched in each nest, and the interval which elapses between 

 the laying of the two eggs, and so between the hatching of the two chickens, is 

 sufficient to account for the discrepancy in their size. One is generally about twice 

 the size of the other in the earlier stages of their existence. The eggs, varying in size 

 from 6*45 cm. to 7 '2 cm. in length, and from 5'0 cm. to 5'5 cm. in breadth (this being 

 the average of ten specimens), are rounded more or less equally at each end, of a white 

 chalky texture without, and are of a green colour within, which by transmitted light is 

 very marked. 



In the majority of the chickens the down is uniformly dark and sooty, but 

 here and there in the progeny of quite normal parents one may find nestlings of so 

 pale a grey as to be almost silvery white with blackish heads, possibly a reversion to 

 an earlier type, and, at any rate, suggestive of the young of the Emperor Penguin, 

 which perhaps represents the oldest stock of all. 



The changes undergone as the nestling grows are well described by Dr. Bowdler 

 Sharpe in the report on the ' Southern Cross ' collections, and, as he there says, the 

 colour of the head is in all cases somewhat blacker in the earlier stages than the 

 remainder of the body. But this difference gradually disappears, owing, no doubt, to 

 the change in the nestling's down, which Mr. Pycraft describes as taking place in this 

 bird before it changes it for the immature first year's plumage. The sooty black, as 

 well as the silver grey, in such as have it, gives way before long to a smoky colour, 

 which gets an old and dusty look by the time it begins to loosen on the under surface 

 of the flippers. This moult begins on the abdomen and the thighs, where the white 

 side stripes appear as the new feathers are disclosed (see fig. 37, p. 52) ; these parts being 

 the first denuded, simply because they bear the brunt of the wear and tear. Then it is 

 shed from the face and head, round the bill, and round the tail. The upper breast 

 and neck and back hold longest to the down, which will by now be clogged with ice 

 and dirt and snow, all of which are abundant in the rookery from time to time. 



