234 BRITISH BIRDS. [vol. xiii. 



On August 23rd I again visited the island, on a perfect 

 summer day. A nest found with the bird sitting on July 8th 

 was found to contain a young one, which I estimated to be 

 about ten days old. In a crevice in which an adult had been 

 found without an egg on July 3rd, there was a chick apparently 

 not more than three days old. These dates tend to confirm 

 the belief that the Petrels sit for not less than thirty-five days ; 

 assuming that in the first case, the bird had been sitting for a 

 day or two on July 8th and that the young one was nearly a 

 fortnight old on August 23rd ; and that in the second case the 

 bird had begun to sit on July i6th or before, and the young 

 one was three days old on August 23rd. On this date some 

 birds were still sitting, but in every case the eggs looked near 

 hatching. On another island I examined several more chicks 

 of various ages, but none appeared to be more than about 

 sixteen days old. I did not once hear the " purring " note. 



On August 27th and 29th I visited another island, and found 

 young ones varying from three days to about four weeks old. 

 In one nest there was an unhatched egg of last year, showing 

 that they use the same nesting crevice every year. 



From the examination of all the chicks found, I made the 

 following observations : — 



Down about half an inch long, of a slate-grey colour. A 

 very conspicuous bare circular patch on the top of the head. 

 Bare white skin round the base of the bill, giving a vulture- 

 like appearance. Skin white aU over the body. Bill and 

 legs and feet white in the newly-hatched chicks, except for 

 the tip of the bill, which is black. They gradually get darker 

 till at about four weeks old they are quite black like the adult. 

 The feathers begin to appear at about this time. 



The chicks keep up an incessant cheeping, something like 

 the note of a young Oystercatcher, and they are consequently 

 easy to locate. The egg-sheU seems to be always left in the 

 nest. 



In shallow nesting places where there is dead grass and 

 other debris among the stones, a sort of rough nest is made, 

 but in the deeper crevices where no material is handy, no nest 

 is made, and the egg is laid on the bare ground. The parent 

 birds brooded the smallest young ones of only a few days old, 

 but no parent bird was ever found with the older ones. It 

 would be interesting to know whether the adults go a long way 

 out to sea during the day, and then feed the young at night. 

 But as I was unable to remain on the island this time, I could 

 not ascertain this or whether the " flighting " is still carried 

 on at night after the young are hatched. 



