Journal of Agricultural Research 
Vol.XIV, No. 6 
236 
constriction two small ones, f\ on opposite sides of a large third one, f, 
the remainder of the original group (fig. 2. G). 
Simultaneously with these divisions a cleavage furrow, cf 1 , appears 
inside each of the five outer cortical groups, b, as shown in figure 2, E. 
These furrows extend laterally until they meet, cutting off a concentric 
ring of tissue which represents the first cycle of the flower—that is, the 
calyx (fig. 2, F). 
When the five inner cortical groups, f (fig. 2, G), have completed 
division, a second set of cleavage furrows, cP, originates, cutting off 
another concentric ring of tissue and leaving in the center a slightly 
oval area, in which are found the four vascular groups, e. 
Simultaneous and progressive changes are now seen in all parts. In 
the calyx the midrib, b, has given rise to groups of vascular tissue (fig. 
2, G, b 1 ), which in some places are still connected, in other places are 
already distinct, forming the lateral veins of the calyx lobes. Each of 
the five bundles (fig. 2, F, g) of the inner cortex which lie opposite the 
midribs of the calyx lobes cuts off a small amount of vascular tissue to 
form two distinct bundles (fig. 2, H, g 1 ). The central portion of the 
tissue of the torus, which is not differentiated, and which contains the 
innermost ring of the four bundles, e, now begins to form the ovary 
proper (fig. 2, G). The first visible change is the appearance of two 
small openings (fig. 2, G, cf 3 ), the convex sides of which are directed 
toward the two smaller of the four vascular groups, e, just mentioned. 
Serial sections show that these openings become larger; the surrounding 
tissue becomes the two carpels of the ovary which are united adaxially. 
The margins of the coherent carpels form more or less evident outgrowths, 
the placentas, which in turn bear the ovules. 
As soon as the cortical groups (fig. 2, H, g 1 ) have become distinct, a 
cleavage furrow (fig. 2, H, cf 4 ) begins to form just below them and 
gradually advancing tangentially cuts off the second cycle of the flower— 
that is, the corolla. This cycle is not of equal width throughout, but is 
constricted and folded at five places to allow for the later expansion of 
the wheel-shaped corolla (fig. 2,1). The midribs and larger lateral veins 
of these lobes of the corolla tube are formed by the inner cortical groups 
f and f t . The vascular tissue of the smaller veins of the corolla is derived 
from the five inner cortical groups, g, which were last to divide. 
The tissue between ovary and corolla becomes radially cleft to form 
the five stamens. Each stamen has for its vascular supply a single 
strand of tissue which is derived from one of the five inner cortical 
groups, g, opposite the calyx lobes (fig. 2, I, g). 
The course of the vascular supply in the flower and the mode of origin 
and course of the traces supplying the different members of the same is 
illustrated in the semidiagrammatic sketch (fig. 2, J). Figure K shows 
a mature though still unopened flower, with its vascular supply in cross 
section through the anthers just above the distal end of the ovary. 
