THE PISTIL. 



97 



not get leaves of firm texture that will hold a pin or a 

 stitch without tearing, try lining them with some thin cloth 

 or paper. Fold each of the leaves at the midrib, with the 

 upper surface inward, as seen in Fig. 288. Fasten the left 

 half of one leaf-blade to the right half of another, so that 



FIG. 289. 



FIG. 288. 



the united portions will form a double wall between the 

 cells, and the six edges will meet together at the center, as 

 represented in Fig. 289. 



Your aim being simply to understand how, and from 

 what, each part of a compound pistil is formed, you need 

 not care for the clumsiness or shapelessness of your manu- 

 factured ovary. 



Point out its cells. Its dissepiments. Explain why 

 they are double. Point out the dorsal and ventral suture 

 of each carpel of your syncarpous structure. Where 

 should you look for ovules in this pistil ? 



Prepare a compound ovary by joining three leaves at 

 their margins, as seen in Fig. 290. In what part of an 

 ovary so formed are the leaf-margins ? In what part of 

 the ovary would you look for the ovules ? The theory 

 that the pistils are made from leaves is important, because 



