22 



BOTANICAL GAZETTE [july 



grow together, dividing the ovary into two cells. One ovule from 

 each placenta is left in each cell. 



The vascular supply of the floral organs 



In the pedicel of a mature flower is to be found a complete ring 

 of vascular tissue. Above this ring breaks up into 26 bundles, three 

 of which pass out to each of the five sepals, five bundles passing 

 up into the tube of the corolla, two large concentric bundles supply 

 the stamens, and four pass up into the ovary. Two of the latter 

 bundles, lying in the sagittal plane of the flower, pass up the car- 

 pellary walls, each giving off two laterals. The laterals die off 

 near the top of the carpel, the medians however passing out into 

 the style, which therefore possesses two bundles. The two remain- 

 ing carpellary bundles branch, each giving off a bundle which 

 supplies the placental wall. The other arm of each forks, the 

 bundles so produced passing up the side walls of the carpel until 

 near the top, where they disappear. Each of the five bundles 

 passing out into the tube of the corolla gives off several branches 

 while passing through the tube. Each of the stamen bundles pass 

 up between two of the bundles of the corolla, being sharply dis- 

 tinguished from them in being concentric instead of collateral. 

 They pass out into the stamens when the latter become free from 

 the corolla tube. 



As we pass down the short pedicel to its insertion, we find the 

 ring first opens on the inner face (figs. 51 and 52). The inflorescence 

 axis shows two large flat bundles, each of which now forks (figs. 51 

 and 52), each of the arms becoming applied to the sides of the 

 opened ring from the pedicel (fig. 53). These two vascular 

 masses then divide to allow the entrance of the single bract trace. 

 The two vascular bundles now tend to round up (fig. 54). In the 

 basal internode this division into two parts is not so marked, as the 

 endodermal sheath usually forms a complete ring around the 

 vascular tissue (fig. 36). 



Discussion 



According to Holm, some of the species of Dianthera which he 

 examined were monostelic. These were D. comata L., D. glabra 

 B. & H., D. inserta Brandg., D. ovata Walt., D. parvifolia B. & H., 



