THE SPRUCE FIR 237 



whole cone grows much larger, attaining a length of 

 from four to six inches. The scales first turn green 

 and then brown, growing hard and woody, and the 

 ovules, as they ripen into seeds, acquire a hard testa. 

 Their wings remain atrached to them, and become dry 

 and membranous. The scales of the cone close firmly 

 together, shutting in the seeds. We thus see that 

 all the parts which constituted the flower are still 

 present in the fruit, which is not often the case in 

 Angiosperms. 



The seeds are ripened in the autumn after flower- 

 ing, but it is only in the following spring that the 

 scales of the cone open out and the seeds fall. The 

 wing to which each seed is attached offers a broad 

 surface to the air, and so enables the seeds to be 

 scattered more widely by the wind. 



The most striking point in the whole history of the 

 female flower is that there is no closed ovary at the 

 time of pollination. When this process takes place, 

 the scales are separated from one another sufficiently 

 to leave an open passage down to the ovules, and it is 

 upon the micropyle of the ovule itself that the pollen 

 falls. There is thus no need for a stigma and a style. 

 On this character, which is common to the whole 

 Class of cone-bearing trees and their allies, the name 

 Gymnosperms, or plants with naked seeds, is based. 



It is only after pollination that the scales close up 

 so as to shelter the developing seeds, opening again 

 when the latter are ripe, and so allowing them to escape. 

 The gymnospermous structure is an obvious difference 

 from other Flowering plants, and will prepare us for 



