14 EDWARD A. WILSON. 
If one forced an old bird with a chicken to move, it would shuffle along awkwardly 
as though the feet were tied together, never exposing the chicken or changing from a 
plantigrade mode of progression. If one hurried such a bird a little more, it would 
over-balance forwards, and try then to retain the chicken with its feet, helping itself 
along with beak and wings. If still pressed to move rapidly, the feet were involun- 
tarily brought into action, and the chicken very soon slipped out behind, being left 
sprawling and piping in the open on the ice to be pounced upon by the nearest 
unemployed adults without delay. 
Obviously, the chickens, as I have said, are common property, and they must 
change hands scores of times while they are dependent upon the adults for their food. 
The method of feeding was precisely as described below in the case of the Adélie 
Penguins. The old bird, having regurgitated some semi-digested food into its 
pharynx, allowed the chicken to supply itself from there by poking its head and bill 
inside the parent's mouth. 
The food of the Emperor Penguin consists mainly of fish and cephalopods, the 
bones and the horny beaks of which are constantly accompanied by pebbles in the 
stomach. Crustaceans of various kinds are eaten as well as fish, but the latter seem to 
form the bulk of their ordinary diet. That so many large birds are able to find food 
for themselves in those southern waters, even in the depth of winter, proves con- 
clusively that there is a great abundance of marine life under the ice throughout the 
year. This, in the case of such animals as Crustaceans, Meduse, Asteroids and Hydrozoa, 
was amply proved by the collections made by Mr. Hodgson, but that fish were so 
abundant we knew mainly by the contents of the stomachs of seals and penguins. 
‘It may seem strange, that during the winter months the sea was not so 
completely frozen over as to prevent the penguins from entering it every day, but 
so it was just where they congregated. 
Floating ice drifts in a direction dependent upon wind and current. If the mass 
is very large, ¢.g., an iceberg, having about seven times the visible bulk submerged, 
the direction of its movement will depend almost wholly on the ocean current, and 
one may constantly see icebergs travelling up the wind. But with flat sheets of 
ice, such as are formed by the freezing of the sea in winter, the wind has 
often a greater directive force than the current of the water. Consequently, along 
the sea face of the Great Ice Barrier, where not only is the set of the water 
current northerly, but the wind as a rule is southerly or easterly, the two combine 
to keep the sea ice on the move in a north-westerly direction, producing, for the 
greater part of the winter, a lane of open water along the actual foot of the ice 
cliffs. Of this the Emperor Penguins take advantage, and here they have an entrance 
to open water always handy. 
If, as very occasionally happens, there is a northerly wind of any strength, the 
sea-ice is driven up to the foot of the Barrier ice cliffs, the channel is for the time being 
closed, and the birds are forced to look for cracks and seals’ holes by which to 
