KEEL-BREASTED BIRDS. 239 
They deposit one egg, that, instead of being placed upon 
the rocks, is held in a pouch until hatched. During this 
time they hop along, the feet being close together to hold 
the egg in ; at other times, when-not holding the egg, they 
walk like other birds. Allied is the jackass- penguin 
(Spheniscus Magellanicus) of the Cape of Good Hope and 
Falkland Islands. The former makes nests for its eggs 
in the rocks, of stones and shells of Ja/anus that are washed 
ashore, 
The rock-hopper penguin * (Zudyptes saltator) is found 
in vast rookeries at Inaccessible Island. From the sides 
of the head projects backward, like a quill-pen, a tuft of 
sulphur-yellow plumes. In the water the wings are used 
as fins. The nests are shallow depressions, containing 
two greenish-white eggs, that are incubated by both male 
and female. 
VaLuE.—Oil, and the skin as fur. At Heard Island the skins are 
used as fuel in the winter. 
Order II. Pygopodes. General Characteristics —The 
birds of this order are aquatic, some with rudimentary 
wings, that are used almost as fins, and covered with scale- 
weeks, when the young appear, and during this time are probably fed 
by the males. The egg is greenish-white and pointed at the end. 
* The rookeries of the rock-hoppers at Inaccessible Island are of 
vast extent, covering one quarter of the island, and giving shelter to 
perhaps five hundred thousand birds, and formed in the vast fields 
of tussock-grass, that is worn out into streets, alleys, and lanes, from 
three to five feet in width. Along these streets the nests of the pen- 
guins are placed; and so fierce are they, and so vast their numbers, 
that a passage through the bird-city is attended by the greatest danger. 
From the sea to the rookery a roadway has been worm smooth by the 
feet of the birds, and up this highway they are seen passing in compa- 
nies and bands. In the water, their motions are similar to those of a 
porpoise, leaping from it in a like manner. They are remarkable for 
their migrations, They leave Inaccessible Island April rsth; the 
males return the last of July, the females August 12th. Where they 
go is not known, and, as there are no landmarks, their return is a won- 
derful example of instinct, and only comparable to that of the seals. 
