PARTS OF ANIMALS, III. ix. 



protection for the viscera about the heart, the loin, 

 in common with all parts that bend, is not so supplied ; 

 and this fat we have been speaking of serves as a 

 safeguard to the kidneys in place of flesh. Further, 

 the kidneys are better able to secrete and to concoct 

 the fluid if they are fat, because fat is hot and heat 

 causes concoction. 



These are the reasons why the kidneys are fat. In 

 all animals, however, the right kidney has less fat 

 than the left. This is because the right-hand side 

 is dry and solid and more adapted for motion than 

 the left ; and motion is an enemy to fat, because it 

 tends to melt it. 



Now it is an advantage to all animals to have fat 

 kidneys, and often they are completely filled with fat. 

 The sheep is an exception : if this happens to a sheep 

 it dies. But even if the kidneys are as fat as can be, 

 there is always some portion which is clear of fat, if 

 not in both kidneys, at any rate in the right one. The 

 reason why this happens solely (or more especially) 

 to sheep is as follows. Some animals have their fat 

 in the form of lard, which is fluid, and thus the wind 

 cannot so easily get shut up within and cause trouble. 

 When this happens, however, it causes rot. Thus, too, 

 in the case of human beings who suffer from their 

 kidneys, although it is an advantage for them to be 

 fat, yet if they become unduly fat, pains result which 

 prove fatal. As for the animals whose fat is in the 

 form of suet, none has such dense suet as the sheep 

 has ; and moreover, in the sheep the amount of it is 

 much greater ; the fact that they get fat about the 

 kidneys much more quickly than any other animal 

 shows this. So when the moisture and the wind get 

 shut up within, rot is produced, which rapidly kills 



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