74 



THE COMMENCEMENT OF THE PHANEROGAMIC FRUIT. 



of the perianth. Of these various kinds of leaves there may be developed one, 

 two, or even more whorls. When several whorled carpels are united together 

 so as to inclose a single chamber, the tip of the receptacle may be produced above 

 the point of insertion of the carpels and project into the ovarian cavity, or it 

 may penetrate the ovary as a central column. On the other hand, each carpel 

 may give rise to a separate chamber, in which case one finds a whorl of distinct 



Fig. 208.— Structure of Phanerogamic Ovaries. 



1 Excavated receptacle and carpels of a Rose (Rosa Schottiana). 2 The same in longitudinal section, s A single carpel of the 

 same in longitudinal section. 4 Ovary of the Apple (Pyrus Mains) in longitudinal section, s xhe same in transverse 

 section. 6 Transverse section of a ripe Apple. 7 Carpel of Cycas revoluta with ovules, a Longitudinal section of an ovule 

 of Cycas. 1, «, ', ^ natural size ; 2, 4 s x 3 ; ' x 8. 



ovaries at the tip of the receptacle (fig. 210^); or there may be numerous small 

 ovaries spirally arranged around the receptacle (figs. 207 ^ and 207 ^). 



In order that the position and mutual relations of the various floral-leaves on 

 disc-like and excavated receptacles may be intelligible it is necessary that we 

 should return to the lump of wax. Let the cone of wax be pressed down so that 

 it assumes the form of a disc or cup. Assuming the floral-leaves to be present 

 upon it during this process — covering the cone from base to apex — when the 

 disc stage is reached the leaves formerly present at the apex will occupy the 

 centre, those at the base the periphery of the disc. If the wax be further 

 moulded into a cup the leaves previously at or near the apex of the cone will 



