GINKGOALES 217 



between Ginkgo and the Taxaceae (44, 47), in which family Ginkgo 

 was placed by the earlier taxonomists as an aberrant member; a 

 connection that will be discussed under Coniferales. The characters 

 in common with the cycads are primitive, shared with Cycadofilicales 

 and Cordaitales; while the characters in common with the conifers 

 are distinctly advanced. At the same time, the foliage and the struc- 

 ture of the strobili are peculiar to Ginkgo. This combination of 

 peculiar characters with others belonging to Cycadales and Conif- 

 erales justifies the separation of Ginkgoales as a coordinate group; 

 and the nature of the characters justifies the conclusion that Ginkgo- 

 ales represent a phylum that has retained certain primitive features 

 in common with the cycadophytes, has advanced more in the direction 

 of the Coniferales, and has developed certain peculiarities of its own. 



LITERATURE CITED 



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