242 WILLIAM TRELEASE— TWO NEW TERMS. 



This unit in angiosperms, neither sporophyte nor gametophyte, 

 gives a first manifestation of crossing in cases where this can be 

 recognized in the forming seed, e. g., when sugary and starchy corn 

 or kinds with colored and colorless endosperm are crossed, where 

 the phenomenon has been called aptly xenia. The transient genera- 

 tion itself, but not necessarily accompanying hybridity, contrasted 

 morphologically with sporophyte and gametophyte though neither, 

 may be designated with convenience and propriety as the 



XENIOPHYTE. 



The significance of this overlooked generation, confined to the 

 most recent and highest of all plants, the angiosperms, not hinted at 

 elsewhere in the Vegetable Kingdom, and originating from the 

 gametophyte in as distinct specialization of gametoid initials as &gg 

 and sperm, is likely to claim serious attention as speculative reasons 

 for evolutionary success and failure come more to the foreground, 

 even though the xeniophyte appears to have reached its term with 

 no more specialized development than the production of a sort of 

 cambium zone and without having achieved the independence pos- 

 sessed by gametophyte and sporophyte — to the latter of which in its 

 most evolved form the xeniophyte now serves as transient host. 



The University of Illinois. 



