336 RELATION OF PHYLLOTAXIS TO MECHANICAL LAWS. 



flattened in the plane passing through the origin, and is thus 

 broader than long ; that is to say, the primordium of such a 

 system is already by construction slightly " dorsiventrally " 



Fig. 111. — Set of five quasi-ciroles of the systems (3 + 5), (2 + 3), (2 + 2), (1 + 2), 

 (1 + 1), arranged for convenience of illustration in diminishing series, 1, 2, 3, 

 4, 6 respectively, along the plane of median bilaterality XY. 



Oi, Cj, O3, O4, O5, the centres of construction, and O3, O4, O5, the origins of 

 respective curves. 



A circle AB, with centre C, has been drawn in contact with the (3 + 5) curve for 

 purposes of comparison. 



bilateral in the median plane. Thus the extreme breadth of the 

 curve as plotted was 11-796 inches, the extreme length 11-304 



