GERMINATION OF SEEDS. 83 



weak plants. (2.) Freshly gathered seeds, as a rule, are 

 preferable to old seeds for sowing 1 and seeds that have never 

 been allowed to become very dry are more likely to grow than 

 those which have been severely dried. This is especially true 

 of most of the kinds of seeds that ripen in early summer, the 

 most of which lose their vitality very quickly when stored. 

 (3.) Some seeds, such as those of the Plum, Cherry and Black 

 Walnut require severe freezing when moist in order to germi- 

 nate. (4. ) Seeds that are covered with water will not gener- 

 ally grow. This is true at least of our northern tree seeds. 

 ( 5. ) The seeds of some trees germinate at a temperature near 

 freezing, while others require a much higher temperature. ( 6. ) 

 After seeds of some plants have become very dry, scalding 

 may aid them in germinating, while with others scalding is in- 

 jurious. It is sometimes desirable to soak seeds for one or two 

 days in tepid water and then mix with sand and freeze before 

 sowing. Lindley records that the seeds found in raspberry 

 jam grew after passing through the heat necessary to boil 

 syrup (240 deg. Fahr. ) and that seeds of Acacia and Lophan- 

 tha grew after being boiled five minutes, but our common tree 

 seeds will not stand such treatment. 



Stratification, as the term is used in this connection, refers 

 to the storing of seeds mixed with layers of earth, leaves or 

 other material. It is customary to apply the term solely to 

 seeds that are mixed in this way and kept frozen- over winter. 

 It is the common practice with the seeds of such trees as the 

 Black Walnut, Hickory, Basswood, Plum, Cherry and Moun- 

 tain Ash. Where only small quantities are to be cared for 

 they are generally mixed in boxes and the boxes buried in 

 well drained soil out of doors, but where large quantities are 

 to be handled they may be mixed with soil on the surface of 

 the ground and left until spring; such a pile is termed a pit. 

 One of the best materials with which to cover seed pits is 

 inverted grass sod. It is a good plan to have the material 

 that is mixed with the seed so fine that it will easily go 

 through a screen and leave the seeds separated for sowing. 



We may conveniently classify seeds into three groups: 

 (1) those that ripen in spring and early summer; (2) decidu- 

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



