144 



LUSSOIfS WITS PLANTS 



always the simple structure which it looks to be 

 from the outside. That is, it may be either simple 



Pia. 144. 

 Flowers of plum. 



or compound. A compound pistil is one which 

 bears evidence of containing two or more united 

 parts or units. The common test of a compound 

 pistil is the presence of more than one locule, 



but this is not always des- 

 ignative, for in some cases 

 false partitions grow out 

 from the walls into the cav- 

 ity of the ovary. The pres- 

 ence of more than one 

 style to a single ovary also 

 indicates a compound pistil; 

 and, more especially, the 

 occurrence of more than 

 one placenta. The separable 

 units or parts in a compound pistil are known as 

 carpels. The theory of a compound pistil is that 



Fia. 145. 



Large parietal placenta of 

 may-apple. 



