. ix.j AND PROPAGATION. 371 



the nest, but never on the eggs, and that this is the 

 mode of proceeding till the male chooses to assume his 

 office of nurse, after which the female pays no attention 

 to them at all. We may wonder how they decide be- 

 tween themselves when this process of real incubation 

 shall begin? Now, the remarkable fact of the Emeus 

 going through the preliminaries of incubation at such a 

 season, can only be accounted for by supposing that the 

 periodicity of the bird's constitution is unchanged, 

 though, by crossing the equator, they find a (to them) 

 reversed occurrence of summer and winter. Lord 

 Derby seems to concur in this view: he says, "Emeus 

 are not the only birds whose times of breeding remain 

 unchanged by their removal to this country. My black 

 Swans breed as often in the winter as at other times. 

 I have known them hatch their young on Christmas 

 day, and rear them quite well, but I believe they breed 

 twice a year at least in England." 



A month subsequently the Emeus were still deter- 

 mined to persevere. "Feb. 12, 1850. My Emeus have 

 now eleven eggs, but I cannot help fearing the effects 

 of this horrid weather for them. It was very cold and 

 rained last evening, with the wind at south-east, but at 

 night the wind went down and shifted to westward or 

 to south-west ; but this morning the rain changed to a 

 heavy fall of snow, and it has been bitterly cold, but the 

 snow has now nearly if not quite vanished again, having 

 no foundation to rest on." Such sloppy miserable 

 weather must be more likely to extinguish the vitality of 

 eggs than a down-right hard clear frost. When incubation 

 was once commenced, the animal heat of so large a bird 

 would drive off all ordinary damp and cold. These un- 

 seasonable proceedings (for England), and their obstinate 



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