SPIRAL ARRANGEMENTS IN PLANTS 



PLATE XI 



25 



Fio. 1. 



l<'if;. 2. 



l''i(i. 3. 



Plate xi. illustrates spiral formations in fir cones and palm trees. 



Fig. 1.- Cones of Finns mantima, collected by the Autlior at San Roniolo, Italy. The ujiper left cone (lateial view) shows double 



spiral arrangement of scales The upper central cone shows a beautiful right-handed spiral, the upper right cone showing a beautiful 



left-handed spiral. These two cones are weathered and the scales opened out by exposure. The lower left and central cones (basal end 



views) shaw the right and left-handed spirals emerging from the axis or stalk of the cone and producing perfect symmetry (compare 



VOL. I. ^ U 



