EXERCISE 102 (Continued) 



4. Two-year-old cones. Examine the scales and seeds. Draw 

 a scale with seeds in position, showing wings of the seeds. 

 Experiment with the seeds, as you did with the fruits of maple 

 etc., to determine their adaptation for dispersal by wind. If 

 mature cones which have not shed their seeds can be secured, 

 allow several of them to lie on the table for several days and 

 note how the seeds are released from the cones. 



5. The embryo. Carefully pick off the hard outer coating of 

 a seed and remove the white interior. Bit by bit, pick off the 

 outer part of the white interior until you come to the embryo 

 within. If you fail on the first one, try another. The large 

 seeds of the pin on, often sold under the name of fine nuts, are 

 particularly satisfactory for this study. Make a drawing of the 

 embryo, showing stem and leaves. Make a diagram showing 

 relative position of embryo, food supply, and seed coat. 



Does the seed of the pine appear to be equivalent to the 

 seeds of flowering plants which you have studied, on such 

 points as means of dispersal, protective covering, food supply, 

 and condition of embryo ? Do you find any weak point in the 

 life history of the pine similar to the gametophyte generation 

 of the fern? 



References 



BERGEN and CALDWELL. Practical Botany, pp. 306-311. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 289-292- 



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