PLANT DEVELOPMENT CONTINUED. 



43 



cape at germination, thus imitating a monocotyledon; 

 here, then, are two endogenous characters. The two 

 cotyledons show its kinship with the Exogens; the stem 

 is imperfectly differentiated into pith, wood, and bark, 

 increasing the exogenous traits. But the pith (cellu- 

 lar tissue) greatly predominates. The flowers are dioe- 

 cious. The males are mere anthers on club-shaped scales, 

 which are arranged in cone-like catkins. The females 

 are naked ovules (Fig. 43), with but one integument or 

 seed-coat (the testa) ; they grow singly, each in the place 

 of a suppressed leaflet, on the lower parts of the compound 

 leaves. 



These leaves form a large cone-like growth at the apex of the stem 

 in the midst of the foliage leaves; and after ripening the fruit, the 

 stem continues to grow upward through this fruit cone, developing 

 leaves and flowers as before. Growth like this, producing a stem from 

 the midst of the flower, is called Proliferous, or race-hearing {L. 

 proles, race). The Cycads are of slow growth, and long-lived. The 

 fruits of some species are large and edible. They belong to tropical 

 countries. 



74. The Cone-bearers (Coniferse) include Yews, Cypresses, 

 and Pines; trees 

 with branches; 

 but the trunks eac- 

 eurrent (running 

 through to the 

 top). The Yews 

 have dioecious 

 flowers. Among 

 them is the hand- 

 some Ginkgo-tree 

 of Japan (Fig. 

 44). Here the 

 male flowers are 

 in long clusters 

 called Catkins; 

 but they are still 

 mere anthers (/) 

 without floral en- 

 velopes. The female flowers (d) are still mere naked 

 ovules without floral envelopes. Each ovule has a disk 



Fig. 44. — Ginkgo (BaJisburia adiantifolia) : ii, /cmale br. ; 

 6, male lir. ; c, male fls. ; d, female fls. ; e, ripe fr. ; f, an- 

 thers. Seduced ; nat. If. 4 inches in diam. ; tree 60 to 70 

 ft. high. 



