THE CARPEL AND OVULE 



289 



there a transverse section shows by its outline, by the arrangement of 

 the vascular strands, and by the position of the ovules that the com- 



Fig. 208. 



Whole gynoecium of Caltha, 

 consisting of many carpels, all 

 separate. 



Fig. 209. 



Pistil, or gynoecium of Lily, show- 

 ing the relative positions of ovary, 

 style, and stigma. F. O. B. 



pound structure is referable in origin to three fused leaves (Fig. 211). 

 Moreover cases of partial fusion are found, for instance in Colchicum, 

 where the three carpels are fused below, but extend upwards as separate 



Fig. 210. 

 Transverse section through the separate 

 carpels, composing the gynoecium of 

 Caltha. F. O. B. 



Fig. til. 

 Transverse section of the syncarpous 

 ovary of Lily, showing the three folded 

 and fused carpellary leaves, bearing 

 ovules on their margins. F. O. B. 



styles. Their relative positions are, however, the same as of those 

 in the completely syncarpous Lily. Biologically the advantage of a 



B.B. 



