112 RELATION OF PHYLLOTAXIS TO MECHANICAL LAWS. 



construction clearer, these have been indicated by triangular areas 

 corresponding to their appearance in the capitulum section. 



The close agreement of an actual specimen with the preceding 



Fig. 45. — Helianthvs annuus. Section of a young capitulum, 10 mm. in diameter : 

 cam. lucid, drawing of half the disk. 



generalisation can be checked on a drawing made from a similar 

 capitulum in the bud stage (fig. 45), and also in the anomalous 

 capitulum (fig. 54). 



Fig. 45, drawn under the camera-Iucida from a young bud 



