134 The Field Nattiralist's Quarterly May 



number of eggs in their first year, making up in weight only 

 during their second season. With wild birds the eggs of the 

 second year are usually larger in size than those of the first 

 season. This is so noticeable with those of the coot that I 

 have frequently heard the first attempts spoken of by our 

 Broadland marshmen as "pullets' eggs." 



We may take the Plover family as representative of the 

 first specification — namely, that the number of eggs in a 

 clutch depends upon the size of the incubating parent. The 

 peewit could not cover more than four eggs, and even that 

 this may be possible those four eggs must be of a certain 

 uniform shape and arranged in a special manner in the 

 nest. The necessity for the eggs being so comparatively 

 large in proportion to the size of the bird which produces 

 them, arises from the nidifugous habits of the young, which 

 must be highly developed on hatching. In proof of the 

 second assertion, reference may be made to the thrushes. 

 How could they feed and tend as large a brood as the par- 

 tridge ? The former parent birds have not only to find the 

 food, but also to convey it to their offspring : this food, chiefly 

 consisting of earthworms, is proportionately heavier to carry 

 and more difficult to procure and prepare than is the insect 

 food of the tits, which are consequently able to provide for 

 more numerous families. The unique breeding habits of 

 the cuckoo have been partly accounted for upon the sup- 

 position that the parent birds laying many eggs could not 

 provide sufficient food for a large brood. Owls surmount a 

 similar difficulty by depositing their eggs at unusually long 

 intervals, commencing incubation after the first egg is laid, 

 and leaving the later eggs to be kept warm by the earlier 

 hatched young, whilst the mother is away hunting for food. 

 The number of eggs laid by any species seems sometimes to 

 have some connection with the number of enemies and 

 adverse circumstances which that species has to contend 

 against, whether the young be nidicolous or nidifugous. 

 Thus those birds which practically spend the greater part 

 of their existence upon the surface of the earth — game-birds 

 on land, and wildfowl on water — lay many eggs, as do also 

 the most fragile of British birds, tits and wrens. 



The number of eggs laid in one nest is fairly uniform in 



