24 BOTANY FOR BEGINNERS CHAP. 



EXPT. 12. Take a few plants of the Couch grass which can be 

 found in most meadows and in cornfields, and examine them. Select 

 one which shows the stolon best. Note 



That the branch is given off above the level of the ground, and then 

 bends downwards and forms a root at the end. 



EXPT. 13. If a piece of a sucker of a Raspberry plant with its attach- 

 ment to the underground stem be obtained, the way in which it is pro- 

 duced can be noted. It will be seen that the underground stem 

 produces a branch, which runs for a short distance beneath the ground 

 and then breaks through the soil and comes to the surface. 



EXPT. 14. Dig up a rhizome, either of Solomon's Seal or a Bracken 

 Fern. To do this it is necessary to have a good trowel with which to 

 remove the surface soil. Follow the stem so as to uncover it without 

 breaking it, and examine. Note 



(i) The old scars produced by the leaves of previous years. These 

 are caused by the dying down of the leaves. 



(ii) The new leaves, which will break through the ground next 

 season. 



(iii) The growing point, which is protected by scale leaves. 



EXPT. 15. Take a Potato tuber and examine it. The eyes, which 

 are buds, will be seen as small dark spots. If a young tuber be examined, 

 the minute scale leaves round the growing point will be seen. Cut a 

 tuber in two and notice how thick and fleshy it is. 



EXPT. 1 6. Obtain a-bulb of the Daffodil and a Crocus corm. Examine 

 and compare them. Note 



(i) The bulb which is made up of scale leaves, many of which are 

 thick and fleshy. 



(ii) In the corm the stem is far larger than in the bulb, but the leaves 

 are not so numerous. 



Parasitic Steins. In a few cases stems are so modified 

 that they can fix themselves to another plant, and extract from 

 it those materials which are necessary for their existence. 

 Plants of this description are called parasites. The Dodder 

 is a good example of such a plant ; it can live on the 

 Clover, the Nettle, and the Willow. When the seeds of the 

 Dodder germinate a long filament is formed, the free end of 

 which moves round and round in search of a host plant as 

 the plant upon which it lives is called and when a suitable 

 plant is found it twines closely about it like a climbing plant. 

 Suckers are produced from those parts of the filament which are 

 in close contact with the host, and these pierce the host, and 

 work their way inwards, to obtain food. 



