PINUS S YL VES TRIS. 1 7 1 



succeeding generation through their sexual or asexual 

 spores, or the division of the vegetative members. In 

 the pine the young plantlet is developed before leaving 

 the parent, and were it to continue to grow would 

 either live wholly upon the parent, or be brought into 

 such close competition with it, that the species would 

 speedily become extinct. Therefore, to provide for 

 the proper dispersion of the offspring, the young 

 plantlet is suitably protected, and provided with food 

 for its first growth when again resuming its develop- 

 ment, separated from the parent, and wafted away by 

 the wind in the utmost security. 



This is one of the most characteristic features of the 

 higher plants, from which they might better have been 

 named seed-bearing plants, than flowering plants. 



It is also worthy of notice that the primary endo- 

 sperm which is formed during the first year of the 

 fruit, and on which the archegonia arise, is subsequently 

 destroyed by the deliquescence of the cell-walls ; and 

 from the protoplasm thus set free there is produced 

 in the spring of the second year what may be called 

 secondary endosperm which, with the growing embryo, 

 fills up the embryo-sac and displaces the most of the 

 tissue of the nucellus. 87 



37 Cf. Sachs, Text-book, 2nd Eng. ed. p. 521. 



