VARYING FECUNDITY IN BIRDS 189 



species. Building in so dangerous a 9. GAME BIRDS. These species [jn 

 position as the open ground, they face England exist under very artificial con- 

 three difficulties, unless they are to ditions, fecundity being encouraged, 

 become extinct : and succeeded by slaughter. Several in- 



The number of young must be large, teresting points of knowledge stand out. 



The young must be able to run when Where a game bird is allowed to 



hatched. revert to natural conditions of less 



The egg must therefore be a very danger, it promptly becomes less fecund 



large one. in the course of a few generations. 



All these difficulties are so sur- Before artificial fecundity was encour- 



mounted that the plover is not becom- aged, the average clutch of " game " 



ing extinct. To ask why it builds in species was not nearly so numerous 



such a silly place would be going back as it is now. The least persecuted 



to first principles. member of the species the ptarmigan 



8. CRAKES AND RAILS. The nest of still has a small clutch, 

 the crake is peculiarly difficult to find. 10. NATATORES. The ordinary rules 

 If a farmer's objection can be openly as applied above hold good with the 

 or surreptitiously surmounted, every birds of this section in general detail, 

 inch of the hay or cornfield has to be while one or two classes present curious 

 searched, for the bird's secret passage confirmations. The egg of the razor-bill 

 through the stems affords no clue, and guillemot is always solitary, and 

 They are tolerably safe from biped or so shaped that any motion imparted 

 quadruped. Why, then, should the to it merely causes it to revolve with 

 clutch be so large seven to nine ? its taper end as a centre, so that no 

 Owing to the excellent cover of the gust or blow can sweep it off the narrow 

 crops, the young need not be large ledge of rock where it is incubated, 

 enough to really fend for themselves If there were more than one egg in a 

 at birth, as must a nestling plover ; clutch, these gyrations would result 

 consequently the eggs are small, and in disaster, and a guillemot's breeding- 

 the hen can incubate a greater number, place in a high wind would be a curious 

 A large number are essential because spectacle. Again, the largest clutches 

 the mowing destroys all late nests and in this order of birds are those pro- 

 many young birds, and there are the duced by the teal and wild duck, 

 usual dangers of migration to be faced, whose nests are peculiarly accessible 



