428 THE ZOOLOGIST. 



near by that contained one egg at 2 p.m. held two at 5 p.m^ 

 The eggs appear to be laid every other day, as a general rule, 

 but there is some variation in this respect, for the interval may 

 be longer or shorter. It may here be noted that a male Gull 

 shot on June 12th showed a large incubation-patch, proof that 

 the males undertake their full share of the incubatory duties. 



As has been shown in this record of observations, both sexes 

 incubate from the laying of the first egg. The following are the 

 the particulars of the hatching-out of four clutches of Herring 

 Gulls' eggs. 

 I. Three eggs. Jane 2drd. One young one out and dry, one 



egg chipped, one unchipped. 

 No change. 



Second out ; third did not hatch ^ 

 One well chipped, one slightly. 

 No change. 

 One out. 

 No change. 

 Second out. 

 One chipped. 

 Two out ; third chipped. 

 Third out. 

 IV. Two eggs. ,, 26th. One just out ; one chipped. 



No change. 

 No change. 

 Second out. 



The shells of hatched eggs are commonly left lying within a 

 few 3'ards of the nest. The Herring-Gull does not void the 

 faeces from the nest. The Kittiwake is the only Gull with which 

 I am acquainted that habitually does so. 



On May 17th two birds were seen jerking their heads and 

 uttering the subdued call, not close together as usual, but one 

 on the island and one on a stone in the water 10 yards away. 

 On another occasion I saw a Gull swimming on the lake going 

 through the jerking ceremony, but its mate on the water by it 

 did not respond. It appears to be unusual for the ceremony to 

 be gone through unless the birds are standing close together on 

 land. In one instance two Gulls were seen together, one of which 

 was uttering the subdued note and jerking ; the other brought 



Three eggs. 



Jane 



23rd. 





>> 



24:th. 





> J 



25th. 



Two eggs. 



jj 



26th. 





j> 



21th. 





j> 



28th. 





>> 



29th. 





)) 



Both. 



Three eggs. 



)> 



25th. 





j> 



26th. 





j> 



21th. 



Two eggs. 



j» 



26th. 





55 



21th. 





55 

 55 



28tk. 

 29th. 



