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NEW YORK STATE MUSEUM 



cell separates by a continuous line, forming a kind of door, which is attached 

 at the top, and turns back, as if on a hinge ; and the anther is said to open 

 by uplifted valves (figure 72). In the Sassafras and certain other members 

 of the Lauraceac, each lobe of the anther opens by two smaller valves, like 

 trapdoors. 



The attachment of the anther to the filament (or stalk) presents three 



different modes, frequently connected 

 by gradation: Innate (figure 70), in 

 which the anther is a direct continua- 

 tion of the axis of the filament, the 

 cells usually opening by marginal slits, 

 and the lobes or cells of the anther 

 project neither inward nor outward; 

 adnate (figure 73), in which the anther 

 is a direct continuation of the filament 

 but having the anther cells adherent 

 to the anterior or posterior face of the 

 filament; the Wild Ginger (Asarum) 

 furnishes a good example of this, on 

 account of a prominent prolongation 

 of the connective or tip of the fila- 

 ment (figure 74); versatile (figure 75), 

 when the anther is attached at some part only of its back or front to the 

 tip of the filament, on which it lightly swings when the pollen is discharged; 

 examples of this are seen in members of the Lily family, the grasses. Evening 

 Primrose (Oenothera biennis) and others. 



73 



75 



Pollination 



The structure of most flowers affords an excellent indication of the 

 device used for the transference of pollen from one flower to another 

 (pollination). Long ago it was assumed that Nature wished no flower to be 

 fertilized by its own pollen, but in the light of present knowledge we know 



