INTRODUCTION. xvii 



safety in an open nest. One of the most striking instances is to be 

 found in the birds forming the genus Malurus. The males are often of 

 the most gorgeous tints, which are assumed exclusively in the nuptial 

 season ; and in many cases, at least, it is known that they do not assist in 

 incubation. There are several possible explanations of these interesting 

 facts. The domed nests may be for the purpose of shielding the sitting bird 

 and its charge from cold, or rain, or from some special enemies. It must also 

 be borne in mind that tliroughout this group the eggs are conspicuous, and 

 this may to some extent influence the mode of nidification. If we grant 

 that these domed nests are built for other purposes than the concealment 

 of the sitting female, it is easy to explain the great diflference of colour 

 between the sexes. The more brilliant colours of the males have been 

 obtained by sexual selection ; for in genera nearly allied to Malurus, such 

 as Stipiturus, Dasyornis, Sphenoeacus, the sexes are alike and dull in 

 colour, but the nests are always domed and the eggs more or less con- 

 spicuous — a convincing proof, I think, that the nests are not so built to 

 conceal any showy colours in the parent birds. As previously stated, in 

 many cases the showy male bird of many of the species belonging to this 

 group assists in incubation, the domed nest allowing him to do so with 

 safety. It is necessary now briefly to notice those 



Birds which do not hatch their own eggs. — The birds that come 

 into this division may be divided into two groups : of one our Common 

 Cuckoo {Cuculus canorus) is a good example, and the other' contains 

 the Megapodes (Megapodidae) or Mound-birds of the Australian Region. 

 The former group will be more fully discussed in the article on the Cuckoo ; 

 and of the latter so little is- known that to Gould's and Hume-'s interesting 

 descriptions little more can be added. It is a wonderful instinct for a 

 bird to bury its eggs in the sand or amongst decaying vegetable matter, 

 and leave them to be hatched by the heat of the sun or the warmth 

 generated by putrefaction. The young, when hatched, are said to break 

 out of their prison and to be able to take care of themselves almost directly 

 afterwards. May not this singular habit, which so closely resembles the 

 mode of propagation of the Turtles and Snakes, be an unchanged inheritance 

 from some semi-reptilian ancestor ? * Let us now glance briefly at 



Birds' Nests. — These structures have long been regarded as one of the 

 most convincing proofs of an instinctive power, a power which is popularly 

 supposed to be almost supernatural, of spontaneous origin, and nearly 

 infallible. Such a belief, as Mr. Wallace very justly remarks, one would 

 naturally expect to find supported by incontestable facts ; but little or 

 nothing can be brought forward in its favour, and the evidence in support 



* Lizards' eggs have been taken from these mounds by Davison (' Stray Feathers,' ii. 

 p. 278). 



