1922.] Mnitnd-huihVnici /yirJs <>/ Aiislr,dia. 709 



hatcliiii<2, tlieiii I)}- means of boat producetl by the fermentation 

 of organic, matter, or wlietlier it: was a [)ai:all('l devcloiiment. 

 This we ciiii he certain of, x'v/,., tiiafc the collecting together 

 of (lead leaves into heaps in order that fermentation may he 

 induced, then the awaiting of the time when the necessary 

 heat was generated and the ascertaining of the correct time 

 when the ferment was on the wane and it became safe for 

 the deposition of the eggs, shows an intelligence of a very 

 high order. 



The case of the Leipoa is still more remarkable. That the 

 rainfall has greatly decreased in the interior of Australia has 

 been sutticiently demonstrated. By reasonable deduction we 

 are safe in asserting that the vegetation of this area will in 

 the past have more or less corresponded with that which 

 now obtains in the habitats of the Jnnglc-Fowl and the 

 Brush-Turkey. 



We are certainly justified in concluding that the Mallee- 

 Fowl, in common with the above-named genera, originally 

 depended entirely for the incubation of its eggs on heat 

 generated Ijy fermenting organic matter. With the reduc- 

 tion of the rainfall a great change took place in the vegetation, 

 ultimately fewer and fewer eggs laid by the Mallee- 

 Fowl were successfully hatched, and the birds were confronted 

 with extermination. There could' have been onlv two 

 alternatives, either a reversion to the methods common to 

 other birds, viz., that of incubation by means of body-heat 

 or the discovery of some new means whereby the temj)erature 

 of the mounds could he raised. This difficulty has been met 

 and overcome by these intelligent birds in the utilization of 

 solar heat. It will be remembered that conjointly with the 

 reduction of the rainfall came an increase in the periods of 

 clear sky and bright sunshine. 



I submit that there is sufficient ascertained data to warrant 

 us in piecing together this page in the past history of the 

 Leipoa. It certainly forms one of the most intelligent and 

 remai'kable cases of the adaptation of habits to chanoed 

 circumstances that can be found in the whole realm of Nature 

 below that of man. 



