ossified sexes were exactly even. 34 nests had addled or infertile or abandoned eggs in them. The balance were empty. All immature birds were able to fly well and all had full stomachs of insects self captured as no feeding by other birds was going on. From time to time birds arrived and rested on nests and later on numbers were noted departing to recommence feeding. Bird guano on floor mixed with bad eggs and dead young nestlings etc. showed the colony was long established). From shortly before dusk to half an hour after dark even birds appeared and settled to roost on nest. Further captures 1 hour after sundown all revealed the same results. 28 immatures up to 1/4 ossified skulls most 1/10 to 1/5 (at least 80 per cent) ossified. Male 15, female 13, stomachs all full. As nearly as possible the same places or close to were used to make captures. Birds did not all leave the colony till nearly 1 hour after sun- rise, only a few left before quarter of an hour after sun- rise then many began to come out. All had left by 1-1/2 hours after and the first began to return about 2-1/2 to 3 hours after sunrise. Observations made at a later date (7/6/38) in cave about 150 yards from the other colony and results were iden- tical (colony smaller only about 100 nests). 12 captures in cave, 2 shot outside close to cave and 2 shot 400 yards from cave. All immatures up to 1/4 ossified skulls, 80 per cent of them 1/5 ossified or less, 9 males, 7 females. On Lifu Island. 1 colony examined on 3/7/38. Surrounding identical cave in sea cliff face (60 feet above