THE EVIDENCE 93 



be simply comparable to other scale-leaves, such 

 as those of recent Cycads, or may be carpels 

 which have ceased to be fertile. On either view 

 there is a great difference from Angiosperms, in 

 which the ovules are enclosed by the carpels that 

 bear them; in Bennettiteae they are enclosed by 

 a distinct set of organs, the sterile scales. It is a 

 little difficult to imagine how the passage could 

 have been made from the one arrangement to the 

 other; the facts rather suggest that we have not 

 yet got the true ancestors of Angiosperms, but 

 only other branches of the same great stock. 



As regards the fourth point, the mode of 

 fertilisation, we have no direct knowledge, 

 for no detailed description of the structure of 

 the gynseceum at the flower stage has yet been 

 published. We know, however, that at a later 

 stage, when the seeds were ripe, they reached the 

 surface of the fruit, their micropyles protruding a 

 little through the narrow openings of the pericarp- 

 wall. Probably this was the case throughout, and 

 if so, the ovules were no doubt fertilised directly, 

 the pollen-grain reaching the micropyle. In 

 other words, the facts point to the Bennettitese 

 having been still Gymnospermous as regards 

 their mode of fertilisation. This, if it were 

 so, is not surprising, for it is not suggested that 

 the Bennettitese were Angiosperms, but only 

 that they were near the probable line of Angio- 

 spermous descent. 



