20 BOTANICAL GAZETTE [july 



case, the development is exactly the same as in the buds of the 

 seedling, having therefore an astelic structure. Each internode 

 has six peripheral and one central bundle, except the basal, in 



may or may 



The 



ordinarily develop into inflorescence axes. As Holm has pointed 

 out, these have a monostelic structure (fig. 36). These buds start 

 their development in the same way as do the buds which develop 

 the rhizomes and stem branches. The first pair of leaves, or rather 

 bracts, first furnish a pair of traces, then the pair of forked bundles 

 develop; the second pair of bracts supply a pair of traces, exactly 

 as in the other kind of bud. The connections of these bundles with 

 each other and with those of the stem on which they are inserted 

 are also as in the branch bud. The pedicel of the single flower 

 developed in the axil of each bract possesses a ring of vascular 

 tissue. At the base this ring splits on the face nearest the bract 

 on one side, and nearest the inflorescence axis on the other. The 

 two halves so produced become inserted between the bract trace 

 and the forked bundle of the inflorescence axis. 



The difference between the structure of the inflorescence axis 

 buds and those forming ordinary branches soon becomes visible. 

 One difference is the greater length of the internodes of the latter- 

 The most important difference between them, however, lies in the 

 fact that in the inflorescence axis, the inner layer of the cortex, 

 while forming a rather irregular sheath around the stele, apparently 



forms a stronglv developed endodermis. This 



but 



remains as a ring, marking the boundary, rather indistinct at 



the 



The paren 



chymatous tissue of the latter differs from that of the former 



made 



smaller 



and in containing a very much 

 The general appearance of a cross- 



monostelic stem 



b 



compare the insertion of a well developed 



with that of an inflorescence axis. Taking a case where the basal 

 internode has no central bundle, we find that the trace of the sub- 

 tending leaf enters between the abaxial side bundles of the branch. 



