c»6 Mattingley, Thermometer-Bird or Mallee-Foivl. f ^^ 



Emu 

 Ocl. 



and study the evolutionary processes that have, perhaps for 

 centuries past, given rise to this elaborate and complicated 

 system of incubation adopted by the Lipoa. We have evidences 

 that birds have evolved from reptiles, that presumedly laid 

 oblong or round white eggs, which they at first deposited 

 haphazard in exposed positions on the surface of the 

 ground. Being conspicuous objects on account of their 

 colour, the eggs were readily preyed upon by enemies, until 

 accidentally perhaps some reptile placed its eggs in a less 

 conspicuous place than usual, and it so happened that 

 it noticed that its eggs were not molested by their 

 usual enemies. Then, having gained the knowledge of the 

 value of protecting its eggs, it repeated the act of purposively 

 hiding them, gaining greater skill and more precise methods each 

 time, and so the habit of covering over or depositing its eggs 

 under bark or stones, or shielding them by covering them over 

 with debris, gradually developed. The covering-up process was 

 thus handed down. As time went on, and as the families split 

 up from the parent stock, they carried this habit with them, 

 each adding some newer or more cunning, more complete or 

 better considered innovation, rendered all the more necessary by 

 the greater degree of skill acquired by their enemies, whose 

 powers of keener observation were being evolved in the same 

 ratio with them. Then those that added newer and more 

 specialized methods of hiding their eggs survived, whilst those 

 members of this branch that did not do so became extinct, or 

 produced coloured eggs to secure some measure of protection — 

 a question simply of the survival of the fittest, and the creation 

 of the different species, aided by natural selection. We have a 

 parallel case in the crocodiles of Australia, which creatures 

 gradually found it necessary to bury their eggs, and afterwards 

 to build mounds of mud to protect them, learning later on the 

 value of placing vegetable material in the mound to generate 

 more warmth to assist the solar heat in hatching their eggs, just 

 as we find them doing in the tropical parts of Australia at the 

 present time. Of recent years crocodiles have found it necessary 

 to further protect their eggs from the depredations of wild pigs, 

 aborigines, and other enemies, and I have often found the 

 mother crocodile lying almost buried in a wallow, out of sight, 

 alongside her egg-mound, as she kept guard. Then, continuing 

 with the process of evolution from that branch of reptiles that 

 evolved birds, from the study of which we find that our feathered 

 friends are merely an extremely modified and aberrant reptilian 

 type, or glorified reptiles — in other words, that the ancestors of 

 birds were four-footed creatures which gradually metamorphosed 

 into feathered bipeds, the fore legs becoming specialized, form- 

 ing wings — then, when we take into consideration the fact 

 that the contour of the eggs of the crocodile and the mound- 



