[Illustration: Fig. 7. "... Which are Frozen into a Compact Mass as Winter approaches" (Page 10)] On Duke of York Island, some twenty miles south of the Cape Adare rookery, another breeding-place has been made. This is a small colony only, as might be expected. Indeed it is difficult to see why the penguins chose this place at all whilst room still exists at the bigger rookery, because Duke of York Island, until late in the season, is cut off from open water by many miles of sea-ice, so that with the exception of an occasional tide crack, or seals' blow holes, the birds of that rookery have no means of getting food except by making a long journey on foot. When the arrivals were streaming up to Cape Adare many were seen to pass by, making in a straight line for Duke of York Island, and so adding another twenty miles on foot to the journey they had already accomplished. When the time arrived for the birds to feed, some open leads had formed about half way across the bay, and those of the Duke of York colony were to be seen streaming over the ice for many miles on their way between the water and their nests. They seem to think nothing of long journeys, however, as in the early season, when unbroken sea-ice intervened between the two rookeries, parties of penguins from Cape Adare actually used to march out and meet their Duke of York friends half way over, presumably for the pleasure of a chat. To realize what this meant, we must remember that an Adélie penguin's eyes being only about twelve inches above the ground when on the march, his horizon is only one mile distant. Thus from Cape Adare he could just see the top of the mountain on Duke of York Island peeping above the horizon _on the clearest day_. In anything like thick weather he could not see it at all, and probably he had never been there. So in the first place, what was it that impelled him to go on this long journey to meet his friends, and when so impelled, what instinct pointed out the way? This of course merely brings us to the old question of migratory instinct, but in the case of the penguin, its horizon is so very short that it is quite evident he possesses a special sense of direction, in addition to the special sense which urged him to go and meet the Duke of York Island contingent, and I may here remark that when we were returning to New Zealand in the summer of 1913, we passed troops of penguins swimming in the open sea far out of sight of land,--an unanswerable reply to those naturalists who still maintain that migrating birds must rely upon their eyes for guidance, and this remark applies equally to the penguins we found on the northern limits of the pack-ice, some five hundred miles from the rookeries to which they would repair the following year. TABLE A