146 



THE LIVING CYCADS 



is shown in Fig. 14, and a closer view is shown in 

 Fig. 81. The sporophylls still show the pinnate char- 

 acter of the vegetative leaf from which they have been 

 derived. 



The cone of Dioon edule illustrates a distinct step in 

 advance (Fig. 82). The axis of the stem has become 

 suddenly and greatly elongated and has produced a 



Fig. ?>i.—Cycas rcvolula: crown of female sporophylls not grouped 

 into a compact cone. 



large number of sporophylls which have lost almost 

 entirely the pinnate character of the foliage leaf but 

 still retain unmistakable evidences of their foliar origin. 

 Even the apex of the axis has become converted into 

 sporophylls, and consequently the growth of that axis 

 is brought to an end. But the checking of the growth 

 of the cone axis results in the formation of a growing- 

 point near the base of the cone stalk, and thus there is 

 established another stem axis, which is really a branch, 



