86 FOREST PLAXTIls^G. 



Elms produce a great many infertile seed pods. Be- 

 fore sowing them they should be examined by a touch of 

 the fingers, and by this manipulation should be ascer- 

 tained whether the seed pods in the center of the round 

 wings are full or empty. Accord.ing to the proportion 

 of empty seed pods, the seed should be used more or 

 less freely. It is not advisable to obtain this seed from 

 dealers, as it will seldom germinate. The grown up 

 trees yield always plenty of seed, and this can be easily 

 gathered by those who want it. 



If broadcast seeding in seed-beds be resorted to, there 

 will be required for the square rod one-quarter of a 

 pound good seed. This is covered by sifting over it a 

 layer of good compost, one-half of an inch thick. 



Broadcast seeding on a larger scale would require 5 

 bushels, or about 15 pounds per acre ; while drilling in 

 rows witli the proper distance (3 feet) could be done with 

 one-half of the quantity of seed named. 



(g) Seed-teds for Alder-trees and Birches. 



Although the Birch and Alder-tree do not rank very 

 high among forest trees, they are valuable in the econ- 

 omy of wood-lands, as they often thrive in localities 

 where no other forest tree would grow, thus preserving 

 the much desired soil-humidity and preventing soil ex- 

 haustion by surface evaporation. They belong to the 

 same order — Betulacece — but differ entirely in their 

 habits and requirements as to soil and situation. 



The Alder is mostly found in wet and swampy grounds, 

 whereas most varieties of the Birch are satisfied with 

 poor, dry and gravely soil, and are not influenced eitlier 

 by the chemical properties of the soil or the nature of 

 the lay. 



The Seed-heds for Birches and Alder-trees are treated 

 exactly like those for Eims, with the exception that 



