[ 21 : 



different European breeds may be fo; and we have 

 reafon to believe, that the bulTaloe, the zebu, and 

 the other varieties that have not yet been tried io 

 Europe, may be blended together. 



2dl)'. The effects of climate and food, in altering 

 the qualities of the breed, are found to be nothing ; 

 though the effeft of thefe things upon the individual 

 creature that is fubjefled to their influence, may in 

 fome cafes be very perceptible. For example : 



It has been fhewn above, that the wool of wool- 

 bearing flieep is affefted by heat or coldj but this 

 is nearly in the fame manner as heat or cold affeft 

 the mercury in the thermometer. It is a momentary 

 impulfe, which ceafes to operate the moment its in- 

 fluence is withdrawn ; and the animal, which may 

 have been made to undergo great variations of hear, 

 returns to its former fl:ate as foon as its original tem-< 

 perature is reftored. But even this variation feems 

 to be felt only by the luool-bearing breeds ; and is, 

 befides, of much lefs powerful influence than has 

 been ufually fuppofed. Nor is there a fingle faft, 

 that ever has been difcovered, that gives the fmallefl: 

 countenance to the generally received opinion, that 

 heat tends either to make the fleece thinner in pile, 

 or to encourage the growth of hairs among it; far 

 lefs that it operates, as M.Buffon and his followers 

 affcrt, in producing permanent changes on t;he de- 

 fceudants of the anunals. 



Heat 



