282 BOTANICAL GAZETTE [October 



stem. The trachea elements of the early stele are strikingly 

 uniform in caliber, pointed at the ends, relatively short, and display 

 no certain delimitation of protoxylem and metaxylem. 



Above the point of separation of the first and subsequent leaf 

 traces a groove commonly occurs in the xylem axis directly opposite 

 the departing strand (figs. 7, 9, n, 15). This is continuous upward 

 a variable distance, where it gradually becomes more shallow and 

 disappears. Not infrequently, however, after the first one or two 

 traces have departed, this groove may detach or be connected 

 internally with a single parenchyma cell which passes up in the 

 center of the trachea group, where it occasionally ends blindly, but 

 more commonly becomes continuous with the sheath parenchyma 

 once more through the embayment of decurrent parenchyma 

 associated with the departure of the succeeding trace. Frequently 



ma 



lateral embayments at the edge of root attachments, similar to 

 that which occasionally accompanies the attachment of the foot. 

 A leaf trace sometimes departs from the stele, which includes 

 parenchyma decurrent from the trace above, without being accom- 

 panied by a break in the xylem cylinder. 



In fig. 8 two included parenchyma cells appear, which are in 

 contact with the sheath above (fig. 9). The embayment occurring 

 opposite the departure of the second trace in this instance does not 

 close up, but becomes continuous with that which isolates the 

 third trace (figs. 10, n). Above the third trace the protostele 

 becomes divided in the plane of the exit of the last trace (fig. 12), 

 but, contrary to expectation, neither segment is exserted as a 



3 



from the seg 





the right at a higher level (fig. 13). The two remaining strands 



fuse almost immediately, and subsequently an indention occurs 



opposite the last trace (figs. 14, 15). This is continuous with a 



group of two parenchyma cells which becomes centrally located 



(fig. 16), and is in contact with the sheath parenchyma again at j 



the departure of the fifth trace (fig. 17). Reference to this series 



shows that five leaves take their departure from the stem before 



the organization of the second root, which appears directly beneath 



and is associated with the sixth leaf (fig. 18). The earliest phyllotaxy 





