598 STRUCTURE AND LIFE HISTORIES 
616. Significance of the "Pteridosperms." The close 
resemblance of the pteridosperms to ferns, on the one hand, 
and to modern cycads on the other, justifies the conclu- 
sion that they represent a "connecting link" between the 
true ferns and the cycads, and that the modern cycads 
have descended from the same ancestry as the modern 
ferns, each developing along somewhat different lines. 
FIG. 420. Stangeria paradoxa Moore. Specimen from the cycad 
house at the New York Botanical Garden, bearing, at the apex of the stem 
a carpellate cone. (Photo from New York Botanical Garden.) 
It was in recognition of their vegetative resemblances that 
the Pteridosperms were first called (by Potonie) Cycado- 
filices, now Cycadofilicales . Van Tieghem tersely de- 
scribed them as "phanerogams without flowers." 
617. A Modern Fern-like Cycad. One of the modern 
cycads (Stangeria paradoxa) 1 is of much interest in this 
1 Stangeria paradoxa Moore = Stangeria eriopus (Kunze) Nash. 
