Lecture XXIII. 203 



Sketch, using the high power, the bordered pits as seen in the three 

 sections. 



Sketch a group of pollen-cones on the supporting branch. Using a simple 

 lens, sketch one cone showing the scales and stamens. Detach a single 

 stamen, and, using the low power or simple lens, sketch it from its upper and 

 lower aspect, showing the pollen-sacs, the mid-rib, and upturned end. 



Shake out some of the pollen on a dry slide and examine with a low power. 

 Observe the central mass and observe its air-bladders. Shake out others into 

 a drop of spirit, cover, examine and sketch. Note the large cell and the 

 small enclosed group of the stalk- and body-cell. Careful examination will 

 reveal one or two of the crack-like vestiges of the temporary cells. 



