252 



GTMNOSPEBMJ!. 



The Gymnosperms are biologically lower than the Angiosperms ; 

 rliev arc wind-fertilised, and without extra floral-nectaries. 



This Division embraces three classes: CYCADEJE, CONIFKRJE, and 

 GNKTK.K. It is no doubt monophyletic, and has taken its origin 

 from heterosporous Ferns, now extinct, most nearly related to the 

 Ophioglossacese and Marattiaceas. The Cycadese appear to be the 

 oldest class. The Conifera? are related to these through Ginkgo. 

 The Gnetacea? are more isolated. The Division is not continued into 

 the higher Flowering-plants ; it has evidently attained its highest 

 development, and is now in a retrograde condition. The similarity 

 which has often been pointed out between certain Coniferae and 

 Lyeopodina? is only in analogous resemblances, and does not entitle 

 one to suppose that there is a nearer relationship, or that the 

 former take their origin from the latter. 



Class i. Cycadeae. 



The stem, is very rarely ramified. The leaves are large, pinnate, 

 and arranged spirally. The flowers are diiecinns, without perianth. 



There is only one order, the Cycadaceae. In habit they 

 resemble the Ferns, especially the Tree-Ferns (compare Figs. 207 

 and -250). The stem is tubercular (Fig. 258), or cylindrical (Fig. 

 2"><>), but not very tall (as much as about 12 metres), and very 



M\ 



h-cinnlix (female plant.). The carpels are seen hanging from the top of 

 stem. Three lesives with the leaflets still rolled up project almost vertically into the 

 :ur, from the centre (if the crown. 



i"iivly minified. [J n Ceylon, unbranched specimens of Cycas are 

 rarely met with in the wild state. The stems of C. circinalis 

 occasionally branch in greenhouses.] 



