SPERMATOPHYTES 



117 



Scattered through the broad tropical belt between the 

 two temperate regions there is another group of modern 



FIG. 94. A Mexican Cycad (Dioon edule). Photograph by CHAMBERLAIN. 



Gymnosperms, called Cycads. They resemble tree ferns, 

 with their columnar trunks bearing crowns of large fern-like 



