CVCADE^E. 



253 



pound (most frequently pinnate ; in Boieenia, 

 bipinnate) ; in some genera the leaves are 

 rolled up in various ways, resembling the 

 vernation in Ferns (Fig. 257) ; they are 

 leathery and perennial. In some, stipules are 

 present, as in the Marattiaceae. Groups of 

 scale-leaves alternate in the majority with 

 groups of foliage-leaves. 



The FLOWERS are without perianth. The 

 MALE FLOWER is sometimes an enormous collec- 

 tion of stamens (Fig. 258), which are flat in 

 some (Cycas, Fig. 241), shield-like in others 

 (Zamia, Ceratozamia) like the sporophylls in 

 Horsetail (Fig.' 259) ; but in all, the pollen- 

 nacs are situated in large and varying numbers on the back of 

 the stamens, and arranged in groups of 2-5, like the sporangia in 

 the sori of the Ferns (Fig. 241 5, c). On germination the micro- 



Fio. 257. Ci/cas cir- 

 cinilis. Part of a young 

 leaf with circinate 

 leaflets. 



FIG. 2-~8. A male plant of Stungeria paradoxa (about 

 j| nat. size). 



FTG. 259. Female cone 

 of Zamia integrifolia (\-$ 

 nn.t. size). The male cone 

 is very similar externally. 



spore contains a bicellular antheridium in the upper end of 

 the pollen-tube ? the vegetative nucleus being found near its 

 lower end. The inner of these two cells is the antheridial cell ; 

 this divides and forms two spermatozoids, with cilia at the 

 anterior end, which swim about in the pollen- chamber, and 

 finally penetrate the archegonium. FEMALE FLOWERS are wanting 

 in Cycas, because the carpels do not terminate the apical growth of 

 the stem. After a group of foliage- and of scale-leaves, a group of 

 carpels is developed, which are pinnate and resemble the foliage- 

 leaves, bearing on their edges a number of ovules (most fre- 



