*0 ON ROOTS. 



i i 



are some parasitical plants,* such as the Viscum album 

 or misletoe, and the Epidendron Vanilla, which, having 

 no immediate communication with the earth, strike their 

 fibres into the stems or branches of a tree, and derive 

 their nourishment from this richly prepared soil ; but as 

 the absorption in this case is not carried on by the regular 

 mode of spongioles,these fibres are not denominated roots. 



A root is never green, even when exposed to the light, 

 an element which is essential to the development of the 

 green color in other parts of the plant. 



The root, then, by means of the little spongioles at- 

 tached to its extremities, sucks up whatever liquid comes 

 within its reach ; in proportion as it grows, its fibres 

 spread themselves over a greater extent of soil, and come 

 in contact with a greater quantity of moisture ; and the 

 plant, whose branches extend above ground, in propor- 

 tion as the root spreads beneath, requires a more abun- 

 dant supply of food. 



Emily. And do the roots take up every kind of liquid, 

 or have they any means of selecting what is suited for 

 their nourishment ? 



Caroline. How would it be possible for them to make 

 a choice, having neither reason nor instinct to direct 

 them For I conclude that the little spongioles are not 

 endowed with the sense of taste, to enable them to dis- 

 criminate betwe-en different sorts of food. 



Emily. True ; but without endowing the vegetable 

 creation with reason, instinct, or even sensibility, Nature 

 might possibly have so constructed the absorbent pores, 

 that, either by mechanical or chemical means they should 

 reject what was unfit, and receive only what was good 

 for the plant. 



* Parasitic, or parasitical plants are those which grow out of another 

 plant, or draw their support from it. The Lichens which cover the epi- 

 dermis of many trees, the Slight which destroys the fruit, and the Seech 

 drops which are attached to the roots of the tree whose name they bear, 

 are all examples of parasitic plants. 



94. What are parasitical plants? 95. What is said of the 

 Viscum album and the Epidendron Vanilla? 96. What parasiti- 

 cal plants are mentioned in the note? 97. What is said of the 

 color of roots'? 98. What produces the color of green in the other 

 parts of the plant'? 99. In what proportion do the branches of plants 

 above ground extend themselves'? 100. What question does Caroline 

 ask concerning the kind of nourishment absorbed by the roots of vegeta- 

 bles'? 101. How does Ernily answer her inquiry 1 ? 102. What is 

 the only provision nature has made to regulate this matter *? 



