66 



BOTANY FOR BEGINNERS 



CHAP. 



number of cells can be seen. These fill up the interspaces, and 

 can be called packing cells, or ground tissu^. 



All the higher plants are built up of tissues. These tissues 

 consist of cells which are grouped together to perform special 

 work. The three kinds of tissues found in the section of the 



stem of the Sun- 

 flower are also 

 found in leaves, 

 roots, and 

 flowers. 



EXPT. 57. If 

 the ground under 

 a Holly Tree be 

 searched during 

 autumn a number 

 of leaves in va- 

 rious stages of de- 

 cay will be found. 

 Some will be 

 found with the 

 soft material de 

 cayed away, 

 leaving a skeleton 

 leaf. The veins 

 of the leaf con- 

 sist of very hard 

 material, and have 

 resisted the action 

 of the atmosphere 

 to a greater extent 

 than the softer 

 material which has 



disappeared. The skeleton leaf consists of vascular tissue, as shown 

 in Fig. 88, where a small quantity of the epidermis and ground tissue 

 is shown near the apex of the leaf. 



EXPT. 58. Obtain an old Cabbage-stalk and cut a transverse 

 section. Such a section is shown in Fig. 89, Examine it with the 

 aid of a hand-lens, and note 



(i) The epidermis, this is shown at A, Fig. 89. 



(ii) A ring of tissue is found between the centre of the stem, see B, 

 Fig. 89, and the epidermis ; this is made up of vascular bundles. 



(iii) In the centre a mass of tissue is found with a number of 

 cavities in ; this is the pith. Between the epidermis and the vascular 

 cylinder a ring of tissue can be seen, which is called the cortex. These 

 cells form the ground tissue of the plant. 



(iv) On the outside of the stalk is seen a number of marks. 



FIG. 87. Transverse section of stem of Sunflower 

 A, epidermis ; B, cortex ; C, vascular ring, (x 7.) 



