Il6 THE HISTORY OF CREATION. 



by the lo-wer main-class, that of Gymnosperms. It was not 

 until the secondary period that the higher main-class, that of 

 Angiosperms, arose out of them. Of these also there existed 

 at first only the lower groups without distinct corollas, the 

 Monocotyledons and the Apetalse. It was not until the 

 chalk period that the higher Corolliflorse developed out of 

 the latter. But even this most highly developed group is 

 represented, in the chalk period, only by the lower stage of 

 Star-flowers, or Diapetalse, and only at quite a late date, 

 in the tertiary period, did the more highly developed Bell- 

 blossoms, Gamopetalge, arise out of them, which at the same 

 time are the most perfect of all flowering plants. Thus, in 

 each succeeding later division of the organic history of the 

 earth the vegetable kingdom gradually rose to a higher 

 degree of perfection and variety. 



