ROOTS. 75 



stem thus planted or layered in the ground give off 

 roots and grow into independent plants. 



But sometimes roots grow from ascending stems, 

 when they are called Aerial Roots. A familiar instance 

 is the ivy, and you know how by these roots it clings 

 to the trees or walls upon which it grows. No doubt 

 we shall pass some as we go along. In the banyan 

 tree, a native of India, these aerial roots are very 

 remarkable. They grow downwards until they reach 

 the earth, where they take root thick and strong, and 

 a single tree thus makes quite a little wood of its 

 own, and may spread over several acres of ground. 

 All these are adventitious roots, and so also are those 

 branch roots which grow upon old root fibres out of 

 the ordinary course of growth. 



As we go home I will just mention some plants 

 which are called Parasites and Saprophytes. The 

 former are called Parasites* because they feed upon 

 other plants, sending down their roots into the plant 

 upon which they live, and from it sucking up their 

 food. A familiar example of a parasitic plant is the 

 mistletoe. But some plants, instead of feeding upon 

 other living plants in the same way which the 

 parasites do, take up food from decaying matter, and 

 these are called Saprophytes, f You will understand 

 more about them when you know more about the 

 physiology of plants. 



* From the Greek "para," beside, and " sites," food ; "parasites," 

 eating at the table of another. 



tFrom the Greek " sapros" decayed, and " phutos" grown, growing 

 (upon). 



