FOREST TREE SEED AND SEED COLLECTING 121 



of all seeds is hastened by soaking them in water for a time before 

 planting. Among special methods of treatment to hasten germi- 

 nation may be mentioned the following^ 



a. When the pericarp or testa is more or less impervious to 

 moisture because of its hardness or leathery character, as in bass- 

 wood, it may be removed in whole or in part. 



6. When the kernel of the seed is cartilaginous in character, as in 

 honey locust and locust, soaking in hot water will hasten germination. 



c. An impervious pericarp or testa may be softened and ren- 

 dered more absorptive by the use of sulphuric acid or potash 

 lye. In using these materials, however, care should be taken not 

 to destroy the vitality of the seed by too prolonged application. 



We have very little definite information regarding the practi- 

 cability of subjecting refractory tree seed to special treatment 

 in order to hasten germination. As a general rule the seed of 

 species that under natural conditions lie over until the second 

 year should be stratified shortly after its maturity and left in 

 the ground until a year from the following spring when it should 

 be removed and sown very early in the season. It is usually less 

 expensive and far more successful than special treatment to 

 hasten germination. It appears from the author's investiga- 

 tions that the only special treatment of practical value is the 

 submerging of certain seeds in hot water for a time before sowing. 



Leguminous seed and a few other species in which the endo- 

 sperm is cartilaginous or horny should be soaked in hot water 

 prior to seeding, using from four to five times as much water as 

 seed. The temperature of the water should vary somewhat for 

 different kinds of seed. The best results with locust are obtained 

 by using water at a temperature of from 190 to 196 F. If boil- 

 ing water is used in large quantity with a small amount of seed, 

 the seed is killed. After the seeds have been placed in the hot 

 water and stirred briskly for a few minutes, the vessel should be 

 set aside until the larger number have swollen to two or three 

 times their normal size. The swollen seeds should be planted im- 

 mediately after their removal from the water. Seeds that resist 

 the first treatment should be treated again. Larch is very irregu- 

 lar in germination, many seed lying over until the second season, 

 particularly when sown late in the spring. Germination is hastened 

 and rendered much more uniform when the seed is subjected to 

 the hot water treatment before seeding. 



