THE EVIDENCE 



65 



The cone consists of an axis bearing great 

 numbers (up to 600) of closely packed scales, 

 which in their turn bear the pollen-sacs. These 

 scales are therefore equivalent to the stamens of 

 Flowering Plants, but they are widely different 

 from them hi structure. The form of the scale 



Fig. 4. Microcycas cdacoma; female plant, bearing a cone. 

 Cuba. After Caldwell. 



is often shield-like, with an enlarged end; some- 

 times it is more like a simple leaf in shape. The 

 pollen-sacs are borne on the lower surface, in 

 large numbers, ranging from a dozen or so in 

 Zamia, to something nice a thousand in Cycas. 

 They are in the same position as the sporangia 

 or spore-sacs on the fronds of Ferns, and like them, 

 they are arranged hi little groups or sori (2-6 



