CHAP, ii.] MR. DARWIN'S ACCOUNT. 261 



would here bring winter, at a period when their consti- 

 tion is, perhaps, least able to withstand it. The impedi- 

 ment has been partly overcome in the case of several 

 Australian birds, such as the Black Swan and the Bronze- 

 winged Pigeons ; but still this game of cross purposes in 

 the seasons may have had something to do with keeping 

 up the line of demarcation in the Fauna of the northern 

 and southern hemispheres, and renders the acquisition of 

 birds that have been long resident, or, if possible, bred 

 in this country, most desirable to the experimentalist. 

 With many birds, as we shall hereafter see, the spring 

 of the south exerts its influence in a northern climate, 

 even after the lapse of many years. 



As to their suitableness for our climate, Mr. Charles 

 Darwin had informed us that " Buenos Ayres is the far- 

 thest point south at which the genus of Guans occurs, 

 and there there are at worst the slightest frosts. I have 

 no doubt the imported birds come from Brazil or Guiana, 

 the climate of which is so like that of India that it must 

 lie in the innate constitution of the bird, if it does not do 

 as well as Peacocks or Poultry. The Guinea-fowl from 

 the dry deserts of Africa has always appeared to me 

 to have withstood a greater change of climate than 

 any other of our poultry. The hen Guans, or birds of 

 the genus, are said sometimes to lay their eggs in a com- 

 mon nest, and if these are reared, it would show that the 

 young must be able to feed themselves." 



The circumstance which induced us to make the trial 

 was a visit to the Surrey Zoological Gardens in the spring 

 of 1848. Of all the choice birds that were there col- 

 lected, a Guan intreated the most earnestly to be trusted 

 with liberty, and promised most faithfully, by voice and 

 manner, to reward the benevolence of its liberator. We 



