150 SCOTCH PINE. 



29. The very tapering ends of the tracheides. 



Cut transverse and longitudinal sections of a young stem 

 collected at flowering time. Examine with a high power, 

 and compare with similar sections of the older stem. Notice 

 the walls and contents of the cells of the several tissues 

 and particularly 



30. The distinctness of the spiral and reticulated vessels. 



31. The deep indentations of the margin of the stem in 

 transverse section, marking the breadth of the scale 

 leaves. 



32. The simple epidermal and hypodermal tissues consti- 

 tuting the bases of the scale leaves. 



Strip off the brown apical portions of the bud-scales from 

 a winter bud and bisect it longitudinally a little to one side 

 of the center. Cut a series of longitudinal sections as uni- 

 formly thin as possible, until the center of the stem has been 

 passed. Mount every section, treat with potash and exam- 

 ine with a low power. Search for the section which 

 includes the center of the axis. It may be recognized by 

 the conical shape of the apex. Note 



33. The central axis or stem.. Observe the arrangement 

 of the cells. 



34. The buds on the side of this axis. Notice 



a. The large scale (base of bud scale) subtending 

 each. . 



b. The central rounded mass of cells, an undevel- 

 oped dwarf branch, covered in by scales. Search 

 for a bud whose central part shows three rounded 

 protuberances. These are the two leaves with the 

 terminal bud of the dwarf branch between them. 

 Draw. 



