166 SEEDING AND PLANTING 



They are preferably made of dark glass to exclude light. When 

 the carboy is filled, it. is corked (with rubber cloth around the cork 

 as a washer) and sealed with pitch. Then the carboys are stored 

 on shelves in a dry, dark cellar, where the mean temperature is 

 44| F. After storage for several years the germination per cent 

 is practically unchanged." 



31. THE STORAGE OF TREE SEED 



All seed that is not sown immediately after cleaning should be 

 carefully stored. The keeping of tree seed in condition to germi- 

 nate when finally sown is often difficult, particularly so with 

 many of our most important species. The essential conditions 

 for storage are the regulation of moisture and a cold, or at least 

 a cool, atmosphere. The different species vary greatly in the 

 amount of moisture required. Even the most resistant species 

 usually suffer when stored over winter in a furnace-heated room, 

 or when kept over summer in a loft where the moisture content 

 of the seed is likely to vary with variations in the humidity of the 

 air. Many species can be safely stored over winter in a well- 

 ventilated, unheated loft. The less resistant species, however, 

 soon lose their viability when stored under normal atmospheric 

 conditions of heat and moisture. The seeds of pine and most 

 other conifers, as well as those of hardwoods like the tulip, black 

 locust, and catalpa, are stored dry, while the seeds of the less re- 

 sistant species, such as walnut, hickory, beech, chestnut, and oak, 

 are stored wet, i.e., under conditions which subject them to a humid 

 atmosphere. If stored in a. dry loft, they soon become shriveled 

 and die, or else their vitality is much impaired. 



Seeds are alive. They represent a dormant stage in the 

 development of the plant. During this stage, however, life 

 processes do not entirely cease. Respiration and transpiration 

 still go on, increasing and decreasing with the increase or decrease 

 in temperature and humidity. Tashiro 1 has observed by the use 

 of special apparatus that even dry seeds give off definite CO2 as 

 long as they are alive. Zederbauer 2 shows that a low tempera- 



1 Tashiro, Shiro: New method of determining vitality of seeds. (Original 

 communications, 8th International Congress of Applied Chemistry, vol. 

 XXVI, p. 163. 1912.) 



2 Zederbauer, E.: Versuche iiber Aufbewahrung von Waldsamereien. 

 (Centralblatt f. d. gesamte Forstwesen, S. 116-121. 1910.) 



