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Church — The Principles of Phy Hot axis. 
a secondary Zone of Elongation , No. i would pull out as a complex 
of spirals in which four distinct sets might be traced ; No. 2 as two 
spiral series leaving paired and opposite members at each f node 5 ; 
No. 3 as a spiral series with two complementary sets only; while 
No. 4 would give the familiar case of alternating whorls with 8 
members at each ‘node.’ Further these cases are not merely arbitrary: 
they may all occur in the plant-kingdom, though the first is admittedly 
Fig. 38. Curve-system (8x8): symmetrical type. 
the most frequent ; but any theory which interprets one should equally 
well interpret the others. Similarly all changes of system may be discussed 
with equal readiness from the standpoint of the addition or loss of certain 
curves, and only from such a standpoint ; since it is evident that once 
it is granted that new curves may be added to or lost from the system, 
the numerical relations of the members may be completely altered by 
