THE BILATBRALITY OF APPENDAGES. 311 



much more striking than in the original log. spiral constructions 

 (fig. 28 (3 + 5)). 



Thus the (2 + 3) system constructed by Archimedean spirals of 

 the second intersection agrees sufficiently well with the phenomena 



Fig. 107. — Geometrical construction (2 + 3) for contact-cycles, in terms of 

 Archimedean spirals of the second intersection. 



observed in the apex of Sempervivum calcaratum (2 + 3) (fig. 108), 

 while the seedling of Nymphaea alba is also clearly (2 + 3) (fig. 

 94). Three members form a cycle in contact round the axis, one 

 being half covered, the other two meeting at their pointed angles 



X 



