THE DIFFERENTIATION OF FLOWER-BUDS 45 



or fibers extend into the leaves, branches, and bracts. A 

 similar though somewhat smaller vascular cylinder exists 

 in the peduncle and from it vascular elements extend into 

 the flowers, leaves, and bracts which it bears. The vascular 

 cylinder becomes smaller and smaller toward the apex of 

 the peduncle, so that at the base of the terminal flower 

 pedicel there remains, usually, but five prominent strands 

 and between them manj^ smaller fibers. These five main 

 strands continue up through the pedicel to well above the 

 middle or toward the apex where each bundle is divided into 

 two, thus forming ten primary bundles. The smaller 

 longitudinal fibers, together with others which branch from 

 the primary bundles, extend in toward the longitudinal 

 median axis of the pedicel. A secondary cylinder is thus 

 formed within the primary one. Just below the apex of the 

 pedicel, these small fibers and others which extend from the 

 ten large bundles previously mentioned, are bent inward 

 toward the small inner cylinder and a confused branching 

 and anastomosing of all the smaller bundles occurs, thus 

 completely eliminating any resemblance to a circular or 

 cylindrical arrangement of the smaller fibers at this point. 

 At the apex of the pedicel, the ten large primary bundles 

 are arranged as an outer and inner cj^cle, each of which 

 consists of five bundles. From each of the bundles of the 

 outer cycle, a prominent bundle extends upward and follows 

 the dorsal line of a carpel. In all, therefore, fifteen distinct 

 bundles and a complex mass of small fibers extend from the 

 pedicel into the fleshy portion of the apple. (See Fig. 20.) 

 The ten primary bundles which diverge at the apex of the 

 pedicel follow closely the so-called core-line of the fruit 

 which has been shown to mark the boundary between the 

 pith and cortical tissues. Each of the main bundles of the 

 outer cycle extends opposite the dorsal suture of a carpel; 

 one of the terminal branches ends in a calyx-lobe, the other 



