150 THE VICTORIAN NATURALIST. 



or lo feet. There was no mistake about this mound being in 

 use, for around and upon it were the marks of the birds' feet, 

 while the surface of the nest itself was ornamented with numerous 

 sticks and twigs. This is a curious habit the birds have of placing 

 sticks upon the crown of their nest. It may be to deceive some 

 natural enemies, or it may be for the purpose of ornament, but in 

 every case where a mound is in use and contains eggs these sticks 

 will be seen strewn over the top. This mound, which was of 

 about the same measurements as the one found the previous day, 

 was also photographed. It, however, was a more neatly finished 

 structure, having a well rounded surface and being ornamented 

 with the abovementioned sticks and twigs placed all over, but 

 more particularly about the crown. Removing these, we pro- 

 ceeded to pull away the sand from the centre, taking care to 

 throw it well back, else the loose dry material would run in again. 

 It was interesting to notice the varying temperature of the mound. 

 On the surface the sand was influenced by the sun's heat. Down 

 a few inches the mound was much cooler, but on going deeper 

 still we could feel the humid warmth of the hotbed of leaves down 

 below. Scraping carefully now, the top of one pink egg was 

 uncovered, then another and another. These three constituted 

 the uppermost layer. Then just below, and partially embedded 

 as it were in the side or bank of leaves, we found four more, thus 

 making a total of seven eggs in the mound. 



While it lasted, the excitement was intense, as, feeling carefully 

 in the sand, we unearthed these eggs one by one. When they 

 were laid out in the sunhght it was comparatively an easy matter 

 to arrange them in order of their age, or priority in the mound. 

 The fresh egg bore a beautiful bloom, while the next in age was 

 not quite so handsome. The fourth egg showed signs of the 

 pinkish colouring changing to a buff or browner tint ; and on the 

 seventh egg even this brown colour was commencing to disappear, 

 for a few whitish smudges or scratches were showing through it 

 about the larger end. From this latter specimen, we concluded 

 that by the time it is about to hatch it could hardly be recognized 

 as the beautiful flesh-pink coloured egg of a few weeks previously. 

 The three oldest eggs, too, bore signs of incubation, for the blood- 

 vessels were forming in the yolks. 



The Mallee Fowl's mound, when examined, is truly a remark- 

 able piece of work, and that a bird should be capable of making 

 such a structure is really wonderful. The source of all the heat 

 generated in this unique incubator is the compact bed of decay- 

 ing leaves in the centre, for the outside layer of sand is un 

 doubtedly to protect the hotbed and concentrate its heat. The 

 birds, if they decide to re-use an old mound, will open it out some 

 time before laying in it. They scratch back the sand so that the 

 hotbed can be replenished. When all is in proper condition, they 



