CYCADALES 



artos, Macrozamia, and Bowenia, however, is the development 

 of a series of secondary cortical cauline bundles by successive sec- 

 ondary cambium cylinders. In these cases the primary cambium 



is short-lived, and a series of secondary cambiums is organized in 

 the cortex, the first giving rise to a vascular cylinder as prominent 

 as the primary one, the second developing much smaller and 



