282 THE VITAL FUNCTIONS. 



the fore leg of the Lion, which is employed 

 in actions of prodigious strength, the artery, 

 without some especial provision, would have 

 been in danger of being compressed by the 

 violent contractions of the muscles : to guard 

 against this inconvenience, it is made to pass 

 through a perforation in the bone itself, where 

 it is completely secure from pressure. In like 

 manner the coffin bone of the Horse is per- 

 forated for the safe conveyance of the arteries 

 going to the foot. 



The energy of every function is regulated 

 in a great measure by the quantity of blood 

 which the organs exercising that function re- 

 ceive. The muscles employed in the most 

 vigorous actions are always found to receive 

 the largest share of blood. It is commonly 

 observed that the right fore leg of quadrupeds, 

 as well as the right arm in man, is stronger 

 than the left. Much of this superior strength 

 is, no doubt, the result of education ; the right 

 arm being habitually more used than the left. 

 But still the different mode in which the arteries 

 are distributed to the two arms constitutes a 

 natural source of inequality. The artery sup- 

 plying the right arm with blood is the first 

 which arises from the aorta ; and it proceeds 

 in a more direct course from the heart than 

 the artery of the left arm, which has its 

 origin in common with the artery of that side 



