;o 



BOTANY FOR BEGINNERS 



CHAP. 



the larger ones in spring and early summer. The small cells are dark 

 coloured ; these form the dark portion of the annual ring. The large 

 cells are light coloured and form the lighter coloured portion of the 

 annual ring. 



EXPT. 66 Cut a radial longitudinal section through a young stem of 

 the Pine. Note 



(i) The cells are cut through lengthwise (Fig. 96), and some of them 

 show a pitted arrangement. 



(ii) A few fine lines will seem to cross the section in different parts ; 

 these are the walls of cells which are cut across transversely. 



EXPT. 67. Prepare a transverse section of a young root of the Pine, 

 which has been kept in spirits for some time. The root should not 



FIG. 96. Radial section 

 of wood of Pins. 

 (X5-) 



FIG. 97. Transverse sec- 

 tion of wood of Pine. 

 (X6.) 



FIG. 98. Transverse sec- 

 tion of young root of 

 Pine. (X 7.) 



be above \ of an inch in diameter. Mount in glycerine. Examine 

 with a hand-lens. Note 



(i) Around the outer part a series of cells which are arranged in 

 regular rows ; these are cork cells, and form the protecting tissue of 

 the root. 



(ii) A number of annual rings which have the same appearance as 

 those seen in the section of the stem of the Lime. 



EXPT. 68. Make a number of transverse sections through the stem 

 of the Rose on which prickles are found. Select a thin section which 

 passes through a prickle. 



If this is examined by the aid of a hand-lens, the prickle will be 

 seen to arise not only from the epidermis (Fig. 99), but also from a 

 portion of the cortex. 



EXPT. 69. Obtain a leaf of the Rhododendron, and bleach it by- 

 placing it in alcohol for a few hours. Cut a thin transverse section. 

 This can be done by placing the leaf between slices of Potato, Carrot, or 

 Elder pith. If a sharp razor be used, and slices be cut across the 

 embedding substance so as to pass through the leaf, a number of sections 

 will be obtained. Place these in water or alcohol in a watch glass, and 



