TREE PHYSIOLOGY 39 



which, descending into the ovaries, add to the tiny 

 ovules the principle which will make them potential 

 trees. Whenever self-fertilisation occurs, degen- 

 eracy is the usual result. 



Scientifically, tree-flowers are modified leaves. 

 Besides the pistils and stamens each one is made 

 up of a calyx, an outer cup-shaped organ, and a 

 corolla or flower proper, which is nearly always 

 divided into petals. 



A tree-fruit is a ripened pistil. Fruits are some- 

 times the product of a number of pistils contained 

 in the same flower, or even of a cluster of flowers. 

 In many trees, the fruits are small and of little 

 food value to man. Occasionally, a tree covers its 

 seeds with generous gifts of juicy and attractive 

 pulps. These fruits become of the highest interest 

 and by careful cultivation are made to attain their 

 maximum development. 



It is a profound thought to realise that the larg- 

 est and most majestic tree was once a tiny seed. 

 In that insignificant offspring of vegetable life was 

 the vital principle which was in essence a tree. The 

 growth and development of the plant was a mere 

 setting in motion of a structure and an organisation 

 already possessed. 



If we examine the embryo forest giant, we find 

 that, in most cases, it contains a radicle or germ of a 



