100 



VII. TBICHOMES WAX. 



form of long rods or filaments, often curved or curled at the end. 

 We remove a surface-section from the nodes of the stem, which 

 are noticeable from their glaucous appearance. As much air 

 clings between the rods, it is best to immerse the section for a short 

 time in cold alcohol ; it can be then readily examined. On the 



FIG. 39. Cross-section through a node of the stem of !3acdiarvm ojfici-narum, with x 

 rod-like wax layer ( x 540). 



other hand, it is difficult to obtain a good cross-section with the 

 rods still adhering. Fig. 39 shows such an one. The rods stand 

 closely crowded together, many showing the flexure already 

 referred to. If a surface-section is brought near a flame, the 

 rods, when examined under the microscope, are seen to be fused 

 together. They dissolve in hot alcohol. 



