IX HEAPS IN THE OPEN AIR. 5o9 



stand autumn-frosts. Air-dried fruits and seeds must therefore 

 be loosely stored so as to admit of moderate ventilation, and over- 

 heating be thus prevented. 



Local climate has considerable influence on the preservation 

 of seed, as is the case in southern districts of Austria. There, 

 in warm winters, acorns sometimes germinate in the pits in 

 which they are stored and become quite rotten by the spring ; 

 when, however, they are kept in dry sheds, the dry air of these 

 districts often renders them as hard as a stone, and they lose all 

 germinative power. 



The choice of sheds or suitable places in the forest for storing 

 seeds depends on the nature of the latter. Whilst beech-nuts 

 and pedunculate acorns may be dried in the forest if spread 

 out thinly, this cannot be done for acorns of the sessile oak, 

 which become over-heated and germinate very readiW. As a 

 rule, it is better to dry seeds under a roof than in the open. 

 Ventilation must not, however, be sufficient to over-harden the 

 seeds so that the kernel separates from the husk. According 

 to experiments made by Braun, fresh acorns when dried as 

 hard as a bone lose 40 % of their weight ; when air-dried, 

 as in airy lofts, 20 ^ ; and in the latter case, 2 ^ of their 

 volume. 



The following are the usual methods of storing seeds. 



2. Storiug in lieaps in the Open Air. 



This method is applicable to beech-nuts, acorns, and chest- 

 nuts. A dry site near a forester's house, with loose, sandy soil 

 for choice, is completely cleared of all vegetable matter, and the 

 fruits are then mixed with plenty of sand and placed in heaps 

 on the ground. The more delicate the fruit, the lower the heaps. 

 The heaps are then covered with dead leaves or straw, at first 

 only moderately thick, and some bundles of straw are stuck 

 through the covering to aftbrd ventilation. As the weather 

 becomes colder earth may be thrown on the covering, but it 

 should always be remembered that seeds are less sensitive to 

 cold than to heat. At the close of winter the covering should 

 be gradually removed in the same way as it was supplied. 



It is extremely probable that the destruction of seeds kept 

 over winter is often due to delay in removing their coverino-. 



