FOSSIL ANGIOSPERMS 279 



complete display of the more primitive Archichlamydeae. A 

 notable introduction during the Tertiary was that of the Legu- 

 iiiinosae. That these appeared first only as Mimosa forms is a 

 strong confirmation of the primitive character of this tribe, -as 

 well as <>f its possible relation to the Rosaceae. 



The above facts in reference to the early history of the Di- 

 cotyledons seem to warrant the following conclusions: 



1. The modern Dicotyledons were derived from a plexus of 

 vague forms developed largely in the Lower Cretaceous and 

 known as Proangiosperms. 



'2. The Cretaceous and Tertiary display is almost exclu- 

 sively made up of Archichlamydeae, the dominant types being 

 the more primitive Archichlamydeae. 



3. The Sympetalae are practically absent from the Creta- 

 ceous and Tertiary, and represent therefore a comparatively 

 recent type. 



4. The possible appearance of Viburnum, associated with 

 Aralia, at the close of the Lower Cretaceous suggests a connec- 

 tion of L^mbellales with the Sympetalae not recognized by tax- 

 onomistfi. 



5. Xone of the highly specialized groups of the Arehichla- 

 mydeae are represented in the Cretaceous and Tertiary, such a 

 family as the Leguminosae being represented by its most primi- 

 tive type, and all the types being what may be called " compre- 

 hensive." 



6. The identity of genera in the eastern and western hemi- 

 spheres indicates the absence of continental diversities, which 

 later became so striking a feature in geographical distribution. 



7. The theory that simple flowers are necessarily reduced 

 rather than primitive structures seems to have a complete refu- 

 tation in the testimony of history. 



