

THE SPRUCE FIR 183 



facility, just prior to the time of pollination the female 

 cone elongates and causes the ovuliferous scales to 

 move wider apart, thus allowing space sufficient for 

 the access of the pollen grains to the ovules. At the 

 time of pollination the ovules are not ripe for fertiliza- 

 tion, and it is about six weeks before that event takes 

 place. The pollen grain falls on to the micropyle of 

 the ovule, where it germinates; in germination a pollen 

 tube is produced, and by the time it reaches the embryo- 

 sac the ovule is ready for fertilization. The seeds are 

 ripe by autumn, but are not liberated until the follow- 

 ing spring, when the scales of the cone open to set them 

 free. The novice will perhaps be glad to have it 

 pointed out to him that the cones which he sees on the 

 trees in winter, or picks up from the ground, are seed- 

 bearers, the ripened results of the female flowers; the 

 male cones, or flowers, disappear when their work of 

 pollen production is fully completed. The seeds, when 

 mature, retain the scales (Fig. 60, C) to which they 

 were attached in their ovule stage; these scales are 

 broad and light, they present a good surface to the air, 

 and enable the seeds to be scattered by wind. The 

 movements of the scales of the female cones at various 

 stages are decidedly interesting. As we have seen, 

 they are moved apart to admit pollen to the ovules; 

 after pollination they close up, and thus protect the 

 ripening seeds. Although seeds are ripe in autumn, the 

 scales still embrace them, as it were, and protect them 

 during the hard times of winter; and it is only in the 

 spring, when germination can be promoted by congenial 

 conditions, that the scales relax their embrace and set 

 their precious charges free. 





