90 PRINCIPLES OF AMERICAN FORESTRY. 



would be very convenient. The nuts are spread over the 

 ground about 18 inches thick, and are stirred frequently 

 until frozen in winter. As soon as they thaw out they 

 are turned once a day. In this way they are prevented 

 from moulding, and from the other injuries that are so 

 common to nuts stored in large quantities. It is desir- 

 able to keep the temperature from ever going much 

 below freezing in such a storehouse. 



Seeds May be Classified Into Three Groups: (1) Those 

 that ripen in spring and early summer, (2) deciduous 

 tree seeds that ripen in autumn, and (3) coniferous tree 

 seeds. 



Seeds that Ripen in Spring and Early Summer (Soft 

 and Red Maple, Elms, Cottonwood, and Willows) should 

 be gathered as soon as ripe, and, with the exception of 

 the Red Elm, sown within a few days or weeks, as they 

 retain their vitality but a short time. (Red Elm seed 

 will not grow until the following spring.) In raising 

 seedlings of this class, it is important to have land that 

 will retain its moisture during the summer months or 

 else that which can be conveniently irrigated, since these 

 seeds must often be sown during very hot, dry weather, 

 and as they cannot be covered deeply they are very liable 

 to fail with any but the best conditions. The thousands 

 of seedlings of Cottonwood, Elm, and Soft Maple that 

 spring up on the sand bars along our rivers and lake shores 

 show what are the best conditions for these seeds to 

 germinate. 



Cottonwood Seedlings can be grown by scattering the 

 branches bearing unopened seed-pods along rows in moist 

 soil and covering the seed lightly when it falls, but they 

 are of so uncertain growth that most of our nurserymen 

 depend upon the sand bars and lake shores for their supply. 



Elm, Soft Maple, and Mulberry seeds generally grow 

 well on any good moist soil. They should be sown 



