126 SEEDING AND PLANTING 



germinative capacity than seed from another tree of the same 

 species. So also seed collected from different parts of the tree 

 often exhibit a wide range in fertility. Thus, tulip fruits from the 

 uppermost part of the crown often contain from 20 to 40 per cent 

 of viable seed, while those from the lower part may be completely 

 sterile. In most pines and other conifers, the position that the seed 

 occupies in the cone determines its relative viability. Thus, in 

 white pine the seeds under the lower and uppermost cone scales 

 are usually small, blind, or otherwise imperfectly developed, while 

 those toward the center of the cone average the highest in fertility. 



Species in which the seed kernel is protected by thin, absorbent 

 coverings usually germinate in a few days or at most in a few 

 weeks; moreover, the germination is comparatively uniform. On 

 the other hand, species having a thick, hard, or leathery pericarp, 

 more or less impervious to moisture, are much slower and more 

 irregular in germination, as is the case with walnut, hickory, chest- 

 nut, beech, oak, cherry, basswood, holly, hawthorn, and haw. In 

 some species, the testa is thick and hard, as in red cedar which 

 requires a year or longer for germination. In the magnolias, per- 

 simmon, and many leguminous species, the seed kernel is hard and 

 horny, and months are required, under normal conditions, for 

 sufficient water absorption to induce germination. Some species 

 appear to require periods of rest before germination takes place 

 even under the most favorable conditions. This is shown in the 

 fact that many species, when subjected to conditions suitable for 

 germination immediately after ripening, require two or three times 

 as long to germinate as when they are subjected to similar condi- 

 tions after a period of storage. 



Even in the most quickly germinating species, a few of the 

 seeds usually lie over and do not germinate for an entire year. 1 

 Seed sown in the autumn or spring that does not germinate by 

 midsummer lies over until the following spring. The seeds of red 

 cedar, cucumber tree, haw, and black gum, which are very slow to 

 germinate and which usually lie over until the second year, some- 

 times germinate in small numbers a few weeks after seeding. 



1 In the spring of 1904, the author gathered 400 seeds of sugar maple that 

 had been lying on the ground over winter. These seeds were immediately 

 sown in a seedbed at New Haven, Conn. An accurate record of germination 

 and later growth was kept. This record showed that 326 seeds germinated 

 hi 14 days, 26 later in the spring, 7 did not germinate until the following 

 spring, and 41 failed to germinate. 



