44 



spaces of the lower portion of the Chart represent at all what 

 would be actually seen on the stem of the infant tree. At the be- 

 ginning of its growth the five ascending leaf-ranks, instead of 

 being widely separated as shown in the Chart, stand in actual con- 

 tact about the slender stem — and continue so throughout the life 

 of the tree. The problem of the Chart, however, is not one of 

 dimension, but of alignment; and for that, Mercator's projection 

 has the great advantage of representing all lines of constant 

 direction as straight lines on a plane surface, and not as conical or 

 conoidal spirals, which all of them save the verticals actually are. 



Within the limits of this short paper it has not been possible 

 to attempt more than a demonstration of the fact and the method 

 of orderly phyllotactic transition from one of the established pat- 

 terns to another. The many and larger questions which grow out 

 ■of this study must await further study. 



Note. — Concerning these the writer will be glad to receive sug- 

 gestions from any one interested in these matters. His address is 

 2639 Durant Ave., Berkeley, Cal. 



Explanation of the Plates. 



Plate I. Plwenix Canariensis. with right-hand primary spiral— clean- 

 shaven below and with fruit-clusters appearing above among the leaves. All 

 traces of Zones I and II have perished, save that a few leaf-scars from the 

 upper edge of II are still visible just at the surface of the ground (Nos. -8, 

 ~i3. —5)- These are the upper ends of 13-ranked secondaries curving sharply 

 upward from the transition zone below to become the vertical ranks of Zone 

 III. Rising obliquely right and left are the 8-ranked and the s-ranked sec- 

 ondaries, the former having the steeper pitch. At the level of leaf 52 the 

 vertical ranks began to incline toward the left, as they enter the transition of 

 ■Zone IV ; causing the grade of the 8's to become a little steeper, and that of 

 the s's to become less steep, as the rotation progresses. At the level of leaves 

 164—169 the transition comes to an end, and the 34-ranked regular pattern 

 "begins so that leaves 198 and 203 stand vertically above the two last named. 



Plate II. Phoenix Canariensis, with left-hand primary spiral, reversing all 

 the alignments of Plate I, and showing a much lower section of the record 

 than is commonly preserved — Zones II (in part). III, IV, and the lower edge 

 •of V. The great curve of the 13's is strikingly shown in its continuous form, 

 without pause at verticality in Zone III, and convex toward the left, turning 

 at about the level of leaves 101-104 into the transition of Zone V. Within 

 the crown of leaves, above, Nos. 161 and 156 may be seen vertically placed 

 above Nos. 127 and 122. Zones III and IV are here much more condensed 

 than in Plate I. 



