88 THE EVOLUTION OF PLANTS 



must thus regard it as a very advanced character, 

 and not at all what we should have expected to 

 find in a Cycad. 



There are, then, three distinct characters 

 in which these Mesozoic Cycadophytes ap- 

 proached the Angiosperms : 



1. In the presence of flowers, organised on 



the same general plan as the typical 

 flowers of Angiosperms. 



2. In the formation of a fruit, enclosing the 



3. In the exalbuminous nature of the seed. 



The coincidence of these various characters 

 can scarcely be without significance, and we 

 seem justified in the conclusion that of all known 

 plants the Bennettitese were the most nearly akin 

 to the Angiosperms. Both from the structure 

 of the embryo and that of the stem it is evident 

 that the affinity was with the Dicotyledons rather 

 than with the Monocotyledons. 



There remain, however, a number of characters 

 in which the fossil family differs strikingly from 

 the Angiosperms; the principal points of difference 

 are: 



1. The habit. 



2. The complexity of the stamens. 



3. The structure of the gynseceum. 



4. The probable mode of fertilisation. 



