234 



PRACTICAL BOTANY. 



FIG. loo. Tangential section of Mountain Ash, show- 

 ing end views of the medullary rays, (x 35.) 



10. Cut transverse, radial, and tangential sections of 

 other arboreous stems. By reference to Figs. 147 and 155 

 identify the various tissues. Maple, Birch, Elder, Elm, 

 Cherry, Apple, and Pear stems are favorable specimens. 



Draw a portion 

 of each section, 

 indicating par- 

 ticularly any 

 differences you 

 find in the same 

 tissue in the dif- 

 ferent stems. 



11. Imbed in 

 paraffin or cel- 

 lo i d i n apical 

 buds of Lilac, Artichoke, or Sunflower, and cut longi- 

 tudinal median 

 sections. Study 

 the thin-walled 

 cells of the api- 

 cal meristem ; 

 these cells have 

 abundant pro- 

 toplasm and are 

 in an actively 

 dividing condi- 

 tion. Near the 

 apex is the grow- 

 ing point. Trace 

 the cells of the 

 apical meristem 



FIG. 156. Transverse section of Mountain Ash, showing 



Stem, and notice a number of annual layers, medullary rays, the large 



thpir rHffWpnti vessels formed in spring growth, and the small vessels 



of late season growth. The right side of the figure 



ation into the was situated towards the center of the stem, (x 35.) 



