CYCADALES 



[CH. 



to surviving species to be included with them in one class, exhibit 

 features regarded by many botanists as indications of an affinity 

 either to true Cycads or to some generalised stock of which they 

 are an offshoot. The Cycads of to-day may fairly be spoken of 

 as anachronisms, plants appropriate to a former age but out of 

 harmony with the present. They are confined to tropical and 

 sub-tropical regions in both the old and new world. In habit 



FIG. 377. Cycas circinalis. From a photograph taken by Mr A. Malins Smith 

 at Teldeniya (Ceylon). 



many of them resemble tree-ferns, but the columnar stem, which 

 may live to a great age and attain a height of 20 metres, differs 

 from that of ferns in its gradually tapered form consequent on 

 the presence of one or more cambial cylinders. Though often 

 unbranched (fig. 377) branching of the main trunk is by no means 



