258 RELATION OF PHYLLOTAXIS TO MECHANICAL LAWS. 



observed in the curve-systems are optical effects produced by 

 elongating the members of the system in a particular way, and the 



Kg. 89.— ffeliamthus annuus. Portion of a young 6-mm. oapitulum, system 

 (34 + 55). Section at the level of the style canals of the developing flowers 

 showing construction quasi-squares, and the oblique setting of the rhomboid 

 ovaries thus "stepping" the "34" curves. Quasi-squares of the comple- 

 mentary (21 + 89) system dotted. 



