VARYING FECUNDITY IN BIRDS. 499 
(3). If (2) be necessary, the egg must be abnormally large for 
the size of the bird. 
Everyone knows how wonderfully these three difficulties are 
surmounted. © 
8. Crakes AND Ratts.—These birds lay from seven to nine 
eggs in well-concealed situations amongst the stems of standing 
grass or grain. Owing to the cover afforded by the stems, the young 
need not be so large when hatched as the young of the Plover ; 
consequently the eggs are much smaller, and the hen can incubate 
a greater number. At the same time it is imperative that she 
should produce a good clutch, for very many nests are destroyed 
when the grass comes to be mown. The birds are also migratory, 
and encounter the usual dangers during passage. 
9. Game Birps lay a good many eggs, as the situation of 
their nests lays them open to many enemies—Stoats, Crows, &c. 
Further, I should not be surprised to learn that they were 
originally less prolific before they were persecuted under the 
name of sport. At any rate, the least persecuted species, the 
Ptarmigan, as a rule lays the fewest eggs. 
10. Coming to the order of Natatorss, I plead guilty to a 
very sinall experience of these birds. Itis obvious enough why 
Razorbills and Guillemots lay but one egg. It is well known that 
their single egg is of such a tapering form that a gust of wind, 
instead of sweeping it from the ledge of rock on which it 1s laid, 
merely causes it to twist round in a circle with the thin end as 
centre. If there were more than one egg in a clutch, these 
gyrations would result in disaster, and a Guillemot’s breeding 
station in a high wind would indeed be a curious spectacle. 
It may further be noticed that the largest clutches in this 
order are those laid by the Teal and Wild Duck, whose nests are 
accessible to many enemies, and who are not altogether free from 
the molestation of man. 
