658 ' STUDIES IN FOSSIL BOTANY 



* 



relation between the Podocarpeae (Taxaceae) and the 

 Araucarieae has been traced, while the position of 

 Cephalotaxus has oscillated between the Taxaceae and 

 the Taxodieae, the latter*being typical Pinoid Conifers. 



Taking all the characters into account, there thus 

 appears to be a decisive balance of evidence in favour 

 of deriving the whole of the Coniferae from the 

 Cordaitales, while not necessarily tracing* them through 

 the particular family Cordaiteae (of whjch, after all, 

 our knowledge is still very narrow). The Conifers 

 thus fall within the great division Pteropsida, though 

 their connection with Ferns is obviously remote, 

 a vast series of more or less primitive Spermophyta 

 lying between. This view involves the conclusion that 

 the microphyllous habit, which characterises so many 

 of the Coniferae, is the result of reduction in the 'leaf, 

 correlated with the increasing ramification of the stem, 

 and also expressing a more perfect adaptation to the 

 conditions of life on dry land. 



The relations of the Ginkgoaceae to the Cycads 

 and Cordaiteae are universally admitted, and need not 

 be further discussed here (pp. 552, 612). 



The characteristic Mesozoic Cycadophyta, the Ben- 

 nettitales, were fully considered in the last chapter. 

 Although the fossil Angiosperms do not fall within the 

 scope of these " Studies," a few words may be added on 

 the relation of the great modern sub-kingdom to the 

 scarcely less dominant Cycadophyta of the Secondary 

 Period. 



The general arrangement of the organs in the 

 Bennettitean fructification, as shown by Dr. Wieland's 



