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already been given in this journal. They need not be repeated here. On 
that hypothesis the formation of one cotyledon from two is due to the 
necessity of reduction in the aerial organs of seedling geophytes. The 
tendency to such reduction is shown in other ways. Among dicotyledons 
the few species which have but one cotyledon are geophilous, so—with 
one exception—are those which have cotyledons united almost to the top. 
In many geophilous forms the cotyledons never appear above ground at 
all, and the first leaf is much reduced in size. Adaptation to a geophilous 
habit also serves to explain many of the other structural features which are 
correlated in monocotyledons with the presence of a single cotyledon, 
notably the stem anatomy. 
But though the collective weight of evidence in favor of this view 
appears to me very great, I have never thought it conclusive. There are 
no facts to make it incredible that the primitive angiosperm was monocot- 
ylous, and that modern dicotyledons derive their two cotyledons from 
division of the original member. That opinion, however, cannot be 
deduced from the evidence just given. It is conceivable that the geophilous 
habit has served simply to specialize monocotyledons, operating to reduce 
the original terminal cotyledon to an apparently lateral one. But that 
hypothesis does nothing to explain the rise of dicotyledons from a monocot- 
ylous race, and it leaves the very marked similarity in vascular structure 
between the primitive liliaceous type and certain geophilous species of 
Ranales out of the question. Yet the approach to a true monocotyledonous 
structure in some of these forms is most striking, and extends to the mature 
as well as the seedling plant. 
In conclusion, I wish again to point out that my purpose in this com- 
munication has been to correct an inconsistency in the former statement 
of my argument, and further to restate a portion of it which has been 
misapprehended. I have purposely abstained from criticism of Mr. 
Lyon’s alternative hypothesis, and from any attempt to answer his criti- 
cisms on mine, except the two which were founded on obscurity in my 
previous writings.—ETHEL SARGANT, Quarry Hill, Reigate, England. 
