i 



THE EVOLUTION OF PLANTS 



233 



to six microsporangia (pollen-sacs) on a stalk. The female 

 cones resembled the male in general appearance, and 

 the seeds resembled those of the Cycadofilicales (Fig. 94). 

 The plant itself was a slender tree, some forms of which 

 attained a height of over 100 feet. The Cordaitales 

 formed the world's first great forests. They represent a 



FIG. 109. Branch, with cones, of the Kauri pine (Agathis australis). 

 (From the Gardener's Chronicle.) 



wide departure from the Cryptogams, and must be con- 

 sidered as true seed-bearing plants. They were closely 

 related to the Ginkgo another living fossil, ranking next 

 below the modern cone-bearing trees. We thus ascend 

 from the ferns to the conifers by a series of transitional 

 forms as follows (reading from the bottom, up) : 



