3 



low is at right angles to the pair abovti. The branches fol- 

 low the same arrangement as the leaves, and evidently for 

 the same purpose. 



8. To gain an idea of the extent of the foliage on a tree 

 some of my students cut a shortleaf pine. It was 5.5 inches 

 in diameter and 30.3 feet high. The crown was 14.2 feet 

 Jong and 9.6 feet across. More than 45,000 needles were 

 counted and weighed: the rest were weighed and the num- 

 ber calculated by proportion. The total for the tree was 

 195,500 needles. More than 500 needles were measured and 

 the average length of the needles was found to be 3.33 inche.<3. 

 The total length of the needles was 65,101,500 inches. 

 Placed end to end they would reach 10.27 miles. The tree 

 had not stood in full light and had a thinner crown than 

 many others. It is probable that the needles on five well- 

 stocked acres of pine timber would more than reach around 

 the world. 



9. Summary;— 



(a) Roots are for;— 



(1) Position or anchorage, 



(2) Absorption. 



(b) Stem and branches are for; — 



(1) Elevation and exposure of foliage, 



(2) Communication between roots and foliage. 



(c) Foliage is for; — 



(1) Preparation of food, 



(2) Respiration, 



(3) Transpiration. 



