198 SCIENTIFIC ILLUSTRATIONS [Lif 



the special circumstances of the soil, dividing their filaments in 

 a soil fit for them almost to infinity, elsewhere abandoning a 

 sterile soil to seek one farther off which is favourable to them ; 

 and as the ground was wide or less hard, wet or dry, heavy or 

 light, sandy or stony, varying their shapes accordingly ? Here 

 are wonderful energy, and illustrations of the way in which 

 existence may be maintained by constant action. v. 



Action and Repose a Law of Life. ' 



There is action and repose even in the life of the tree. The 

 circulation of the sap in the tree is in its most active state in 

 the springtime. The plant is then full of liquid, and in new 

 plants the juices flow at the slightest incision. In spring, accord- 

 ing to the poetical expression consecrated by use, the vine and 

 other plants bleed ; but when the leaves are fully developed, 

 they will no longer bleed when wounded. When the branches 

 develop themselves and consolidate, the movement of the sap 

 becomes slower; it is sometimes roused towards the end of 

 summer, when, the spring having been premature, the materials 

 which the plant has elaborated for the vegetation of the follow- 

 ing year have been set to work before their time. After the 

 fall of the leaf, and when the approach of winter lowers the 

 temperature, the movement of sap is stopped entirely ; the tree 

 arrives by little and little at a state of almost absolute repose : this 

 is not death, but life which awaits its re-awakening. In human 

 life we have, but still more plainly written, this same law. 

 From youth to manhood, and from manhood to old age, how 

 incessant is the activity during all but the few hours allotted 

 to repose ! As Ovid says, 



" Alternate rest and labour long endure." 



And at the end of all the activity, and the last long repose, which 

 seems but is not death, are we not, also, like the tree, to have 

 our re-awakening in a day to dawn as surely and as brightly as 

 the spring? v. 



