176 SAGACITY AND MORALITY OF PLANTS. 



These external wrappers are called '' bracts." They 

 are undeveloped leaves, or in other words, they are 

 leaves whose duty it has been to sacrifice them- 

 selves for the benefit of those inner leaves they are 

 thus protecting from the winter's cold. They will 

 never see the " promised land " of next summer — 

 will never wave green in the gentle summer breezes, 

 or be visited by the singing birds. They will die 

 in view of the " promised land," for when the in- 

 creasing heat and light of the early summer cause 

 the leaf- buds to develop and increase in size, these 

 brown sticky bracts will be forced to drop off, and 

 perchance we may see the ground underneath the 

 trees strewn with them in April and May. The 

 principle of altruism (" self-sacrifice " and " heroism ") 

 is thus abundantly represented even in the vegetable 

 kingdom. The manner in which the bracts cover 

 over and protect the winter leaf-buds is not confined 

 to one method. Thus those of the Lilac are green, 

 but tough and leathery ; those of the Mountain 

 Ash are lined with wool — a capital non-conductor 

 of external cold as well as heat. In the larger leaf- 

 buds we always find some contrivance of this kind 

 to keep the extreme cold from affecting the deli- 

 cate inner leaves. In very small leaf- buds, such as 

 those of the Hawthorn, the bracts or external leaf- 

 bud wrappers are of a reddish -brown colour, and 

 when leaf-buds are so small there is no doubt their 

 diminutive size is in their favour. They are not 



