54 DA VET'S PRIMER 



Attention ! children. Now, all of you raise your 

 hands over your heads and feel around. Do you feel 

 anything? "No!" Well, there is something there, 

 and we could not live without it ; it is called "oxygen." 



The untold billions of leaves are engaged making 

 this. Before vegetation existed animals could not live. 

 Look at those marvelous veins ! See how they branch, 

 much like the veins in your hand. The largest are the 

 midveins, from them branch off the veinlets and veinu- 

 lets. The leaves on the trees stand through hot days 

 and chilly nights, taking the water that the faithful 

 little roots send up, spread it out to the rays of the 

 glorious sun, and there in that mysterious labora- 

 tory the leaf the oxygen is manufactured, and sent 

 forth on the wings of the wind. Have you not noticed 

 what large-bodied men and women some of your grand- 

 parents are? Well, they lived in or near the woods, in 

 early days, and their lungs were filled with this life- 

 giving substance. Some of our city people are very 

 small and weakly compared with these old frontiers- 

 men and women. 



The leaf does many other things ; it manufactures 

 starch and sugar, and stores them up in the wood of the 

 tree. But one of the most valuable things it does 

 is to gather up the carbonic acid gas that you breathe 

 out a deadly poison to you. The leaf greedily con- 

 sumes this and makes it into wood. Surely then we 

 are very foolish to destroy that which takes from us the 

 poisons, and gives to us that substance without which 

 we could not live the oxygen. 



Children, you should have reverence for the leaf. 



