48 EDWARD A. WILSON. 
Ross Sea was then frozen over as far as the eye could reach, and only a very 
few lanes of water were visible, from which frost smoke was rising here and there, 
but ten days later the sea was open and every scrap of ice had been blown by 
recent winds to the Northern horizon, where, as a long glistening line of pack ice, 
it could be seen shining in the sun. The area of the rookery at Cape Crozier is 
immense, and runs up the valleys and slopes of Mount Terror from the sea shore to a 
height of from 700 to 1,000 feet. The main valley in which it lies has a facing almost 
north, and is for some reason bare of snow. On the eastern limit are two very old and 
weatherworn blue-ice cliffs, which are remnants of a previous and more extensive 
glaciation. On the 29th October our visit to the rookery was made in a heavy gale of 
wind with thick snowdrift from the S.W., but we found that in the rookery valley we 
were completely sheltered. The prevailing wind there was more nor’westerly than 
southerly, as we could see by the sastrugi or ridges in the snowdrifts. 
The nesting sites are arranged with some method, not here and there as the 
builders fancy, but in groups with neutral ground between them, each group varying 
in point of numbers from twenty upwards, and relying upon a few of the most pugna- 
cious members for defence. From ten days to a fortnight after their arrival the birds 
begin to lay, and when each nest contains two eggs the serious incubation begins. 
Lasting from thirty-one to thirty-four days—three days elapsing between the laying of 
the eggs, according to Mr. Evans of the ‘Southern Cross’ Expedition—the business of 
incubation is shared by the cock as well as by the hen, and at Cape Royds I had the 
opportunity of seeing the two change places. The hen presumably was sitting on the 
eggs when the cock came up to her, and she presently stood up. Then began the weird 
motions that go on in courting times. Standing breast to breast each rubbed its neck 
against the other’s, first one side and then the other alternately, with a gentle cackle all 
the time (fig. 36, p. 48). The cock was now and again allowed to see the eggs and touch 
them with his beak and rearrange a stone or two of the nest, and this went on for several 
minutes, she loath to go, and he, I presume, assuring her the while that she should 
go and get some shrimps, for there is no fasting during the period of incubation, as 
some have stated; presently the hen stepped off and the cock at once walked in and 
commenced to sit upon the eggs. I was surprised in this case that two eggs should 
remain so long unhatched, and turned the bird off to examine them. One egg had 
a pinhole in the side, but I had not the heart to disillusion them, and so they went on 
sitting. Probably the other one was addled. 
The climatic conditions which these birds undergo are by no means so severe as 
those which the Emperor Penguin faces, but they are severe enough in their way. 
During the winter months from May to August, wandering between S. latitude 61° on 
the Antarctic Circle, the bird weathers long nights of darkness, much cold and many 
snowstorms ; but probably the conditions here are very much less severe than those 
given by M. Henryk Arctowski, in his account of the meteorology of the pack in 
winter, between 70° and 71° S. latitude, some ten degrees farther to the south. 
