74 IMPROVEMENT OF THE BRBEDS. 



fCQ.) C/ian(/es produced bt/ Climate.^— The wondor- 

 ful power of temperature in effecting changes upon 

 animals, is well illustrated by the Portuguese, who, 

 after a residence of three hundred years in India, are 

 said to be at present almost as black as Caffres. 

 Bishop Heber, si)eaking of India, says, " It is remark- 

 able to observe how surely all these classes of men 

 (whites — Persians, Greeks, Tartars, Turks, and Ara- 

 bians), in a few generations, even without any inter- 

 marriage with the Hindoos, assume the deep olive tint, 

 little less dark than a negro, which seems natural to 

 the climate. Buchanan also in his travels through the 

 same country, alludes to a tribe of black Jews who 

 have, in all probability, been settled in the district ever 

 since the period of the captivity under Nebuchadnezzar, 

 3000 years ago, and who retain all the national pecu- 

 liarities of their race, with the exception of their 

 colour, which is now as dark as that of the surround- 

 ing tribes. These examples, however, it maybe affirmed, 

 are not to the point, as embracing theories in regard to 

 peculiar changes in an animal different from the sheep, 

 but such objections are perfectly groundless, as what 

 will affect colour in mankind, will lead to changes even 

 of a more wonderful nature in the sheep, seeing that 

 it is abandoned more entirely to such an influence. 



(70.) Temperature preferred by Sheep — Sheep, 

 though capable of thriving in a great variety of climates, 

 seem to prefer such as are temperate, and in these 

 only do they arrive at perfection. They are common 

 on the Cordilleras at an elevation of from .3300 to 

 8200 feet, within which limits they propagate readily 

 without any care ; but the reverse is the case in hot- 



