26 DA VET'S PRIMER 



Do you know how the inside of a tree is con- 

 structed, children ? 



Perhaps not, I will therefore tell you. 



It is built of little cells, attached one to the other. 

 Through these the sap, gathered by the faithful roots, 

 of which we shall say more, passes from one to the 

 other, even out to the farthermost twig. These cells are 

 wonderfully arranged. In some respects they resemble 

 the " mains " of a water works system. The sap flows 

 onward, upward in a certain system of cells, and turns 

 off on this main street (branch), while that in the 

 other goes out into another street (branch), etc. Now, 

 suppose you cut off a branch and leave a "stub," as 

 you see on page 23 ; death sets in on the remaining 

 " stub," and though nature tries to heal, she is unable 

 to do it while this obstacle the stub is in the way. 

 After some years the stub rots off, but the decay has 

 followed down, down, down ! and a damage has been 

 done that may shorten the life of the tree two-thirds, 

 or more. 



Did you ever try to count a million? Well, 

 what will you think when I tell you that in Ohio alone 

 there are millions of these wounds, opening inroads of 

 decay and destruction on our friends, the trees ! and the 

 same is true in other states. If the branch is properly 

 removed, and a nice, clean cut made, close to the trunk 

 or branch from which it comes, it will heal, as you see 

 in this photograph. 



A branch of any size may be taken off, but it is 



