4o8 



STRUCTURE AND LIFE HISTORIES 



362. Gymnospenny,— The fact that the seed is not 

 enclosed within the carpels, or walls of the ovary, but 

 continues wholly exposed throughout its existence, until 



Fig. 303. — Cycas media. Germinating seeds, e, endosperm (gameto- 

 phyte); c, cotyledons; st, leaf -stalk; h, hypocotyl, showing early enlarge- 

 ment to form the thick trunk shown in Fig. 291. 



shed, is one of the most significant of all the features of 

 the cycads. On this feature, and its opposite, the great 

 division of seed-bearing plants (Spermatophytes) is sepa- 

 rated into two classes as follows : 



Spermatophytes 



Gymnosperms 



Angiosperms 



The word gymnosperm means "naked seed,"^ while 

 ' From the Greek, gymnos {yutiv6s), naked + sperma (<r?rep;uo), seed. 



