486 
Church. — Note on Phy Hot axis. 
radial direction as they approach the centre that they cannot 
possibly represent any formation of primordia at the stem- 
apex, on which such members are well known to arise as fairly 
isodiametric protuberances. At the same time, it will be 
noticed that the Archimedean spirals by construction all fall 
into the centre and stop there, so that no room is left in the 
Fig. 2. Theory of Schimper and Braun. Construction for Phyllotaxis A- 
OA. = Orthostichy line = radius vector passing through i, 22, 43, &c. Members 
along the contact parastichies differ by 8 and 13 respectively. Genetic spiral 
winds left. Divergence-angle =-^- of 360° = 137° 8' 34". 
system for any subsequent growth and the addition of new 
members which naturally obtains in the plant 
Again, further consideration shows that all spirals, whatever 
their primary nature may have been, must necessarily pass 
