THEIR REPRODUCTION (NESTS) 269 



These long-legged birds, as we have already 

 seen, frequent marshes and lagoons. They 

 build a most extraordinary nest, a tall conical 

 pillar of mud, with a shallow cavity at the apex 

 for the eggs. This structure is most beautifully 

 adapted to the conditions of nidification, being 

 either built in shallow water or so near to the 

 margin and in swamps subject to more or less 

 sudden inundation. 



The thoughtful reader may well ask the 

 meaning of all this wonderful architecture, the 

 motive for such varying means for ensuring 

 the safe maturity of the eggs. It is not, how- 

 ever, the protection of the eggs that is the sole 

 consideration, the safety of the incubating parent 

 is of no less importance — safety, be it remem- 

 bered, at a time when the usual means for secur- 

 ing it are not so readily available, and various 

 exceptional dangers have to be guarded against. 

 To a very great extent (even to a degree that 

 amounts practically- to a Law) the colour of the 

 parent's plumage is correlated with the manner 

 of nidification. To understand the facts it will 

 be necessary to divide birds into various classes 

 quite irrespective of their taxonomic affinities, 

 but according to the relation between the colours 

 of their plumage and the methods of their 

 nidification. 



