414 BOTANICAL GAZETTE [December 



Meanwhile the single nucellus of the ovary grows downward from 

 one side (fig. 14), thus making the ovarian cavity appear crescentic 

 in its upper half when seen in cross-section (fig. 18). This cavity 

 in the lower portion about the hanging micropylar end of the 

 ovule is completely circular in form (fig. n OvC, upper flower). 



With the further growth of the ovary the ovarian cavity is 

 extended upward by the stylar canal which opens out on the side 

 of the style opposite the subtending bract (figs. 14 SyC 7 22). The 

 lower part of this ovarian cavity at the time the embryo sac is 

 mature extends downward as an inverted conical chamber for 

 half the distance to the base of the ovary (fig. 22). During the 

 maturing of the fruit the cavity is filled by the single seed (fig. 42). 



The style and stigma are developed by the continued growth 

 of the upper margin of the carpellary ring, after the latter has 

 closed together above the ovule to form the distinct stylar canal 

 (figs. 14, 22). The stigma is formed solely from the longer lip 

 of the upgr owing carpel (fig. 22). It consists, at the time of 

 pollination, of a flattened triangular surface, the cells of which are 

 parenchymatous. Later, in the ripe fruit, the mature stigma 

 shrivels and disappears. The style is rather short. Internally 

 it consists of two or more layers of elongated cells of small diameter 

 which border on the stylar canal and probably serve as conducting 

 tissue for the pollen tube (fig. 22). Around these layers of con- 

 ducting tissue are 15 layers of other cells. 



Early in its development the wall of the ovary consists of about 

 10 layers of cells (fig. 14). At the time the embryo sac is ripe the 

 ovarian wall opposite the pore of the perianth is often 15 cells in 

 thickness. Of the 15 layers of cells constituting the ovarian wall, 

 only the 7 outer ones are appreciably specialized in structure. 

 The epidermis becomes gradually cutinized as the embryo sac 

 matures, and papillose cells arise in the exposed area where the 

 perianth does not at first cover the carpellary wall. The cutin 

 layer on the walls of these cells is thickest opposite the pore in the 

 perianth, and becomes gradually thinner in the epidermal cells 

 farther away from it. 



At this stage, also, the 6 layers of cells within the epidermis of 

 the ovary are strikingly irregular in contour. The 3 layers immedi- 



