THE ADDLED EGG 319 



Why should the dabchick, after the hatching of its 

 eggs, leave its own nest, in which it has hitherto sat, 

 and sit in those of another bird ? I examined the nest 

 thus deserted, and found it to be sinking down in the 

 water, which was still more the case with some other 

 and older ones. This, I believe, is the answer to the 

 above question. The bird's own nest is no longer 

 quite comfortable, and others are to hand which are 

 more so. Having stayed, therefore, as long as its 

 incubatory instinct prompts it to, it resorts to these, 

 and being no longer tied to one, uses several. But a 

 habit at one time of the year, might be extended to 

 another time, and if certain dabchicks were to take 

 to sitting in the nests of moorhens, before they had 

 made their own, some of these birds, whose nest- 

 building instinct was weaker than in most, or who, 

 finding themselves in a nest, imagined that they had 

 made it themselves which, I think, is possible 

 might conceivably lay their eggs there. It would 

 then, in my opinion, be more likely that the usurping 

 bird should remain, and hatch out, possibly, with its 

 own, some one or more eggs of the bird it had dis- 

 possessed, than that the contrary process should come 

 about. 1 However, the first business of a field 

 naturalist ("and such a one do I profess myself") 

 is to make out what does occur, and this I have 

 tried to do. 



I think it curious that neither of the two pairs of 

 birds that 1 watched, hatched out, apparently, more 

 than three of their eggs. The first pair certainly did 

 not, and I saw the fourth egg in the nest of the 

 second, after the birds had left it for another one, 

 1 See ante, pp. 131, 132. 



