66 



BOTANICAL GAZETTE 



[JULY 



unlignified cells may vary. Often the arrangement shows the 

 protoxylem point on each side of the cylinder, with a band of 

 unlignified cells arranged parallel to it and just inside, while the 

 middle of the cylinder is occupied by a band of phloem extending 



Figs. 4-7.— Fig. 4, L. carinatum: transverse section of the strobilus apex, show- 

 ing the development of the parallel-banded type; P x, protoxylem; p, phloem; fig. 5, 

 L cannalum: transverse section of the stele in the strobilus axis, showing the amphiva- 

 sal condition, phloem in the center inclosed by a ring of xylem; px, protoxylem; 

 p, phloem; fig. 6, L. Phlegmaria: transverse section of strobilus, showing radial 

 arrangement, with the phloem extending across the center forming a band; the same 

 condition is also found in L. carinatum; px, protoxvlem; p, phloem; fig. 7, L. Phleg- 

 maria: showing the development of the parallel-banded stele; px, protoxylem; p, 

 phloem; all X500. ' 



