SlY. PT., x9o3[ THE CONDOR ?23 ing their own burrows where there is soil enough, or using a crevice in the rocks if it is small and deep, while the guillemots will use a larger and more exposed crevice under a boulder. The auklets are very plentiful on these islands, less so, however, than on the islands farther south along the Lower California coast, where sandy soil offers every opportunity for them to excavate long and perfect burrows. At this date, June 3, the auklets all had eggs and very few were fresh, incubation being apparently about half completed. These Cassin auklets are curious little fellows, preferring to do their foraging and courting at night and keeping out of sight during the day. Every night and all night long they keep up a constant talking and calling, flying about in the dark with apparent ease. At the eastern end of the island is located one of the most curious sights of the place: Murre Cave it is called, and is in fact a great narrow vertical cleft in the cliff, facing seaward and rather difficult of access. It extends into the cliff for CALIFORNIA M URRE: perhaps too feet, and there is a broad ledge or bench about half way in, and the whole place is alive with the tourres. They sit close together, breast to back, side to side, till the cave is lined with their snowy breasts and sooty heads. They were uneasy at our approach, but few left till we had been inside for some little time. Then the leaders started, and after them came a stream of tourres that kept in- creasing in volume till the air was full and the mouth of the cave was vomiting a cloud of birds, like smoke pouring out of a chimney. The tourres were nesting in other colonies at various places about the island, one great colony being on a rock just off shore on the north side. At this date they had barely started laying. We found only a few eggs, fresh laid, and this was evidently the reason that the birds were shy and easily disturbed. Had we been three weeks later, when all would have been found incubating, we would doubtless have been able to go mnongst them without disturbing them very much, as they are fearful of leaving their eggs on account of the robbing of the gulls.
