INTRODUCTION 7 



10. Seeds are fertilized ovules, structures which when 

 mature include rudimentary plants (embryos) protected 

 while dormant by seed coats and containing nutriment 

 either in or around the cotyledons to supply the needs 

 of growth. Since the production of seeds is due to the 

 fertilization of ovules by pollen, the process is called 

 sexual ; hence the term sexual reproduction is often 

 extended to include seedage. In beet, chard, and some 



FIG. 5 WEEDING POTTED PLANTS IN COLD FRAME 



other plants, the "seeds" are really the dried fruits or 

 capsules which contain several to many seeds (p. 49). 



11. Seeds vary greatly in size from that of the dust-like 

 orchid and begonia to that of Seychelles cocoanuts, 

 which sometimes weigh 40 pounds, and are 18 inches in 

 girth. 



12. The micropyle is a minute opening through the 

 seed coats. Through it the pollen tube enters the ovule 

 and the radicle emerges during the process of germina- 

 tion. Often it is almost invisible until the seeds begin to 



