
32 THE AMERICAN NATURALIST. (VoL. XXXIX. 
more than a suspensor at the tip of which the metacormal pri- 
mordia are differentiated (Fig. 11). 
The suspensor of a gymnosperm embryo is clearly not homol- 
ogous to that of a lycopod or angiosperm embryo. In the gym- 
nosperms, the suspensor is developed between the body of the 
protocorm and the blastema and by its elongation serves to sepa- 
rate these two structures. In the lycopods and angiosperms, it is 
an outgrowth from the protocorm and has one free end. In 
these embryos the metacormal axis is differentiated through the 
body of the protocorm. . 
Polyembryony sometimes occurs in both gymnosperms and 
angiosperms through the production of two or more blastemata 
by one protocorm. 
UNIVERSITY OF MINNESOTA. 

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