CYCADALES 



i6i 



Have the Cycadales left any progeny? Something has left some 

 progeny; for an abundant progeny, both gymnosperm and angio- 

 sperm, is very visible and very much alive. What groups could have 

 been responsible? 



If we consider only the nine living genera of cycads, the answer is 

 easy: They are not responsible; they are the last of their race, re- 

 stricted in geographical dis- 

 tribution, restricted in num- 

 bers, and struggling for their 

 very existence. 



What progeny exists for 

 which an ancestry should be 

 found? The only possibilities 

 are the Cordaitales, Gink- 

 goales, Coniferales, Gnetales, 

 and the angiosperms. We do 

 not believe that any of these 

 owe their origin to the cy- 

 cads, but shall venture some 

 speculations in dealing with 

 the Coniferophytes. 



We should feel consider- 

 able confidence in conclud- 

 ing that the line, Filicales, 

 Cycadofilicales, and Cycadales, is a genetic line, as thoroughly 

 established as any line extending over so great a period. 



/// 



Fig. 176. — Cycadospadix hennoquei: a meg- 

 asporophyll rather closely resembling that of 

 Cycas revoliita. — After Zeiller.''^ 



Fig. 177. — Cycadospadix milleriana: mega- 

 sporophylls collected into a loose cone, which 

 must have stopped the growth of the axis. The 

 axis could not have persisted as in the female 

 plant of Cycas revoluta. — After Renault, i^s 



TAXONOMY 



The ideal taxonomy should be based upon life-histories and phy- 

 logeny. Unfortunately, the taxonomy of the Cycadales has suffered 

 more than that of most groups, because the people who have made 

 most of the descriptions hav£ never studied cycads in the field. 

 Microcycas, so large that one can climb around among its branches, 

 and not looking at all like Cycas, would never have received such a 

 name if the taxonomist had seen it in the field. But even such mis- 

 nomers are not so bad as names given to commemorate those whose 

 names would otherwise be lost; or those who would be remembered 



