190 THE HOUSE I LIVE IN. 



A wound with the point of the smallest 

 needle gives us pain, but this could not be, un- 

 less there were nerves in the part which is 

 wounded. I suppose they are so numerous 

 that if there were any way of destroying all 

 parts of the human body except the nerves, 

 without in the slightest degree injuring or dis- 

 placing the latter, they would present a large 

 mass whitish, indeed, and not quite so firm 

 but resembling, in shape, the complete and 

 perfect living body. The arteries the vessels 

 which carry blood from the heart to all parts of 

 the body if all else were destroyed, would 

 probably present the same appearance ; and so 

 would the veins. This shows, in a most strik- 

 ing manner, that each of these parts of the 

 frame must be very numerous. 



There is however one important difference 

 between the nerves and the blood vessels. 

 The latter are all hollow tubes, but the nerves 

 are not known to be so. The large ones cer- 

 tainly are not. Some have supposed that the 

 little white pulpy threads or fibres of which 

 they are all made up are hollow ; but this too 

 is not very probable. 



