FERNS, FOSSILS AND FUEL 
great tree-fern of New Zealand, or some large tree-wind¬ 
ing tropical fern, but they bore seeds of all sizes, by which 
they reproduced themselves. 
The spermatophytes proper are divided into two 
groups: the gymnosperms, which have free seeds either 
entirely uncovered or merely attached to the scales of 
cones, and the angiosperms, the seeds of which are always 
in capsules. Gymnos in Greek means naked, and angios 
covered; so their names describe them as naked-seed 
plants and covered-seed plants. 
The gymnosperms are divided into a number of orders 
which are in turn subdivided into families, genera, and 
species. The most important of these groups is the 
cycads or sago palms. Related to the cycads is another 
group which played an important role in previous geologic 
times, called the bennettitales or Cycadeoideae. Another 
group is represented today by the gingko tree, a queer form 
related to the cone-bearing trees, but having a fan-shaped, 
rather stiff leaf. It is an ancient tree that has defied 
time and looks today almost as it did millions of years 
ago. It would probably have died out but for the Brah¬ 
mins and Buddhists of the East, who selected it for their 
temple arbors and by cultivation perpetuated its life. 
No longer growing wild, it flourishes in parks and botan¬ 
ical gardens where magnificent specimens are to be seen. 
38 
