6io 



STRUCTURE AND LIFE HISTORIES 



The leaves of Cordaites resembled those of the Kauri 

 pines (Agathis) of the southern hemisphere (Fig. 431), 

 or the leaflets of Zamia. They varied from a decimeter to 

 over a meter in length. The male cones resembled those 

 of the still living Ginkgo, each stamen having from four 

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



FIG. 431. Branch, with cones, of the Kauri pine (Agathis australis). 

 (From Gardener's Chronicle.) 



cones resembled the male in general appearance, and 

 the seecls resembled those of the Cycadofilicales (Fig. 423). 

 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 

 wide departure from the Cryptogams, and must be con- 

 sidered as true seed-bearing plants. They were closely 



