454 



STRUCTURE AND LIFE HISTORIES 



" seed-leaves/' or cotyledons, and on this basis Ray 

 (1628-1705), the noted English botanist, divided the 

 class of Angiosperms into two large sub-classes mono- 



FIG. 338. Morphology of typical monocotyledonous plant. A, leaf, 

 parallel- veined; B, portion of stem, showing irregular distribution of vas- 

 cular bundles; C, ground plan of flower (the parts in 3*5); D, top view of 

 flower; E, seed, showing monocotyledonous embryo. 



cotyledons and dicotyledons. 1 These two groups are dis- 

 tinguished by other characters which are quite con- 



1 Plants like Pinus having more than two cotyledons are poly cotyledons. 



