PIN US S YL VES THIS. 1 5 I 



35. The conical apex, growing point, of the axis. Notice 

 the scales which cover it. 



Examine with a high power. Study both the growing 

 leaves and the apex of the stem. Note 



36. The shape of the cells, which in these regions are cap- 

 able of division and are collectively known as the 

 primary meristem. 



37. A short distance behind the growing apex, the cells of 

 the primary meristem become differentiated, some 

 becoming elongated and fusiform and others forming 

 the spiral vessels. Trace them further and further from 

 the growing point and notice that the differentiation 

 constantly increases. 



38. On the sides of the section, just behind the conical 

 point, one or two elevations, the apices of the axes of 

 lateral buds of the succeeding season. Draw the 

 apex. 



B. THE LEAVES. Cut a transverse section of one of 

 the older needle leaves below the middle. Examine with a 

 low power, and note 



1. The shape of the section. 



2. The three distinct regions it presents : 



a. The narrow outer cortical region, whitish in color. 



b. The central oval fibro-vascular region, bounded by 

 a distinct chain of cells, the bundle sheath. 



c. Between these two regions, a zone of green (green- 

 ish even in alcoholic specimens) parenchyma, the 

 mtsophyll. 



3. The number and position of the resin ducts. 



4. Make a sketch of the section. 



