80 THE EVOLUTION OF PLANTS 



from Luccombe Chine in the Isle of Wight; in 

 this species the structure of the fruit was first 

 revealed by the work of Carrathers and Solms- 

 Laubach. Other European specimens have con- 

 tributed much to our knowledge, but the most 

 important results of all have come from the in- 

 vestigation of the rich American material, during 

 the last ten years or so, by Dr. Wieland of Yale. 

 To him we owe our first knowledge of the structure 

 of the flowers, a word which, as we shall see, may 

 appropriately be used for the fructifications of 

 these plants. About sixty species have been dis- 

 tinguished from the American Upper Jurassic 

 and Lower Cretaceous rocks; the individual 

 specimens are extraordinarily abundant; from 

 the Black Hills of Dakota alone, nearly a thousand 

 silicified trunks, referred to twenty-nine species, 

 have been obtained. 



In general aspect the Bennettitese resemble the 

 shorter-stemmed Cycads of the present day; none 

 are known to have attained any very great height; 

 the leaves were scarcely different from those of 

 such recent Cycads as Zamia. The stem was 

 clothed with an armour of leaf-bases, but there is 

 one peculiarity which at once distinguishes these 

 fossil trunks from those of any living Cycads. In 

 the Bennettiteae we find, scattered among the 

 bases of the leaves, the scars of leafy branches re- 

 sembling large buds; these are the remains of the 



