On one such occasion I witnessed an interesting little incident. An imprisoned hen was poking her neck up through her breathing hole when her mate spied her and came up. He appeared to be very angry with her for remaining so long on the nest, being unable to grasp the reason, and after swearing at her for some time he started to peck at her head, she retaliating as far as her cramped position would allow. When she withdrew her head, he thrust his down the hole till she drove it out again, and as this state of things seemed to be going on indefinitely, I came up and loosened the crust of snow which imprisoned her, on which she burst out, and seemed glad to do so. She was covered with mire, having for many days been sitting in a pool of thaw water which had swamped her nest and evidently spoilt the eggs. When I put her back on the nest, she sat there for some time, but eventually they both deserted. I should say that some hundreds of nests were spoilt in this way. [Illustration: Fig. 65. ADÉLIES ON THE ICE-FOOT] As I photographed the above incident at intervals, different stages are seen on Figs. 67 to 69. I have mentioned that eggs got lost owing to cocks fighting among the nests. When hens are incubating the eggs they never leave the nest under any circumstances until relieved by their mates, being most reliable and faithful to their charge. They squabble continually with their nearest neighbours, whom they seem to hate, but only retaliate on those within reach, using their bills only to peck at each other's heads without shifting their position. The cocks, however, are less dependable. Starting a quarrel in the same way as the hens do, their militant instincts soon became aroused, on which they are apt to jump up and start a furious fight with flippers, staggering to and fro over their nests, and very often spilling the eggs, which are lost in consequence. On certain occasions I was able to interfere between the combatants, and replace the eggs, on which they would return to their domestic duties and seem to forget the incident. A good many eggs must have been lost in this way during the season. Late in the season an occurrence took place for which I have never been able to find any explanation. Occasionally I had noticed that the penguins had crowded together more than usual on the ice-foot, multitudes of them standing for hours without any apparent purpose. A good idea of this scene may be got from the frontispiece. One morning Mr. Priestley came into the hut and told me that "the penguins were drilling on the sea-ice," and that I had better come and look at them. I went with him to the ice-foot, and this is what we saw.