256 BIRDS OF MIDDLESEX. 



having young hatched while others had empty nests, 

 or only a single fresh egg. Again, it appeared that 

 incubation commences as soon as the first egg is 

 laid, for some nests contained both eggs and young 

 birds. 



The nests, as usual, were placed on the ground 

 within a few feet of each other, and were, for the 

 most part, built in tussocks of coarse grass, and 

 composed entirely of the same material. The ma- 

 jority of them contained three eggs each, but many 

 had four, and, in a few instances, I noticed three 

 eggs, cracked, and a young bird. Several of the 

 young birds, two or three days old, were running 

 about or hiding in the coarse herbage, while over- 

 head, it might be safely asserted, hundreds of the 

 parent birds were dashing about on outstretched 

 wings, rending the air with their wild screams. It 

 was truly a beautiful and interesting sight ! The 

 variety which exists in eggs of the Blackheaded Gull 

 is very curious, and, if we except those of the Com- 

 mon Guillemot, perhaps no other eggs vary so much. 

 I may mention a few of the most marked varieties 

 which I have taken, the common type being dark 

 olive-brown, with dark spots and blotches. — Var. 1. 

 Green, with darker spots or blotches. Var. 2. Light 

 grey, with olive blotches. Var. 3. Pale sea-green, 

 with a zone of brown spots at larger end. Var. 4. 

 Pale bluish white, with scarcely any markings at all. 



There is no breeding station of the Blackheaded 



