ANIMAL LIFE. 407 



The complicated net-work of vessels which co- 

 vers the internal surface of the nostrils, offers an 

 easy passage to the blood when its momentum is 

 suddenly increased ; and as no other part of the 

 body is similarly constituted, bearing the same 

 relation to this external circulation, the blood will 

 flow from the nose in preference to any other 

 part of the system.* 



CCCCLXXXVIII. DrCciLLEN says, that "an 

 hemoptysis may be expected to happen from a 

 faulty proportion between the capacity of the 

 lungs and that of the rest of the body." This 

 reasoning appears perfectly correct; but I cannot 

 perceive the justness of what follows, " that an 

 hemoptysis will especially happen about the 

 time that the body is approaching to its acme, 

 that is, when the system of the aorta has arrived 

 at its utmost extension and resistance." Accord- 

 ing to this opinion, hemoptysis does not occur 

 in childhood, because the aorta accommodates 

 itself to every additional quantity of blood. The 

 thoracic viscera in infancy and childhood are ex- 

 tremely active, and from the great expirations 

 and violent exertion of individuals at a tender 

 age, we should certainly anticipate derange- 



* It may probably be asked, Why does it not flow from the 

 anus ? In answer to a question of this kind, I may observe, 

 tbat the mucous membrane of the nose is highly vascular, as 

 the seat of a sense j and, from its proximity to the thoracic 

 organs, more liable to be disturbed by those causes that in- 

 crease the impetus of the blood. 



