THE PISTIL. 89 



Roughly to imitate a multiple pistil, you have 

 only to bind together, by their petioles, several leaf- 

 blades that have been converted into carpels, as 

 above. Observe the placentation of any multiple 

 pistil, and you will invariably find that the placenta 

 of each carpel is central in the same way that, in the 

 artificial one, you have made the margins of your 

 carpellary leaves turn inward, and the midribs out- 

 ward. 



After thus preparing simple and multiple pistils 

 from foliage leaves, let us try to construct a com- 

 pound pistil from leaf-blades. If we can do this, it 

 will give us a clear understanding of the structure of 

 syncarpous ovaries. 



Form, from foliage leaves, an artificial ovary, of 

 three coherent carpels. A three-celled compound 

 pistil consists of three carpellary leaves grown to- 

 gether. It is as if, by pressing together the carpels 

 of your multiple pistil, they should unite by their 

 sides. To make an artificial compound pistil, then, 

 you have only to select three large symmetrical foli- 

 age leaves, and pin or stitch them together in such 

 a way that their margins will meet in the centre, and 

 their under surfaces will form its outer wall. If you 

 cannot get leaves of firm texture that will hold a pin 

 or 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. 

 166. Fasten the left half of one leaf-blade' to the 

 right half of another, so that the united portions 

 will form a double wall between the cells, and the 

 six edges will meet together at the centre, as repre- 

 sented in Fig. 167. 



