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 

 a millimeter 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 seeds 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 



