The Effect of Westerly Winds on the Flight of Gulls. 423 



in a nest -with young found last season in a cave^ one of 

 the parents was white and the other blue. 



11. Pelecanus conspicillatus. {Australian Pelican.) 



About a dozen pairs of these birds nested on the Penguin 

 Rocks on a small patch of clear ground just above high- 

 Mater mark, and surrounded with high tussocky grass. The 

 nests were very simple : a few sticks and bits of grass put 

 together and almost level with the ground. There were 

 one or two eggs or young in the nests, the latter being of 

 various ages, from about three weeks old downwards. One 

 little one, about three days old, managed in the absence of 

 its parents to crawl from its rightful nest into that of its 

 neighbour, which contained a bird about three weeks old. 

 The elder bird immediately commenced vigorously pecking 

 the little stranger, and would soon have killed it had the 

 latter not been removed. 



The young had no down on and their skin was bare; 

 the regular lines of growth where the young feathers were 

 appearing were plainly discernible. When they crawl they 

 appear to stick their beaks into the soft soil and thus to pull 

 themselves along, as they have not power to stand up and 

 walk. 



There ajDpears to be some little time between the hatchings 

 of the eggs in the same clutch, as one young bird was 

 noticed being hatched while its companion was about seven 

 days old ; and in a clutch of two eggs taken, one was about 

 five days more incubated than the other. Two eggs 

 measured:— (1) 3-66 inches x2-24j (2) 3'67x2-25. 



XXXIV.— 0;« the Effect of Westerly Winds on the Flight of 

 Gulls (Laridse) and other Birds. By J. H. Gurney. 



In all birds it appears that wind, or the force of wind, is 

 the prime mover in flight — that is to say, the action of the 

 wings is greatly regulated by the direction and velocity of 

 the windj though, joined to this, the actual motive power is 

 gravitation to the earth's surface. If there is absolutely no 



