PINUS 187 



tude of the one-year-old cones with that of the cones 

 at the time of pollination. 



2. Study these cones as directed above (H, i-n), com- 

 paring the older and the younger organs. En- 

 deavor to explain any differences observed. 



3 . Record the length and greatest diameter of the one- 

 year-old cone, and make a drawing of it, natural 

 size. 



O. The Two-year-old Carpellate Cone: 



1. Record, its position on the branch, its attitude, and 

 dimensions. Compare it, in these points, with the 

 young, and one-year-old cqnes. Draw, natural 

 size. 



2. Make drawings of a detached scale as seen from 

 (a) the outer (dorsal) surface, (b) the inner (ventral) 

 surface, (c) the side. Describe any changes 

 observed in the appearance and relation of the 

 various points. 



3. Note that the ovule has developed into a winged 

 seed. 



P. The Seed: 1 



1 . The seeds are usually shed from the pine cone during 

 the third summer, about two years and a quarter 

 after pollination. 



2. Record the dimensions, shape, and character of the 

 surface of the seed. The small depression in the 

 smaller end of the seed locates the micropyle, which 

 is now grown together. Draw, natural size. 



3. Let fall from a height of several feet a seed of some 

 species having wings still attached, and note the 

 approximate time required to reach the ground. 

 Remove the wing and repeat the observation. Sug- 



^he large seeds of the nut-pine, Pinus edulis, or of Pinus pinea, may 

 advantageously be used for this study. 



