VEGETABLE LIFE. 189 



left. This is also, to a considerable extent, the case 

 with plants. Wounds will heal over, and when the 

 edges of the leaf of an evergreen, such as a laurel, 

 are killed by the frost in winter, they will exfoliate, 

 and the sound part of the leaf will retain its vitality 

 and cicatrise at the edges ; but if there is a canker in 

 the living part of the tree, the place always remains 

 unsightly, and the canker is apt to spread. A clean 

 wound in a stone-fruit tree, too, such as a cherry or a 

 plum, soon heals ; whereas, one that is produced by 

 natural disease, though much smaller than the other, 

 will continue to exude gum during the whole of the 

 warm season. 



VEGETABLE LIFE 



is indeed one of the most curious subjects in nature, 

 and as one cannot move a step in the Spring without 

 meeting with a new display of it, it is then a constant 

 object of study, and he who does not attend to it must 

 be dull and incurious in an extreme degree. 



One of its most striking qualities is, that it is 

 always the more energetic, the less space that it oc- 

 cupies ; and that the diminution of the space over 

 which it is diffused, is the general means by which it 

 is preserved from the extremes of temperature. Most 

 of the herbaceous plants in those tropical regions of 

 the world, which have burning suns and cloudless 

 skies for months, die down into their bulbs, to the 

 very bottom of which the active principle retreats, and 

 remains in the radical plate protected by the mass of 

 fleshy matter above it; and the quantity of that matter 

 is always sufficient to prevent that plate from rising 



