THE PARTS OF THE PISTIL 



143 



place where the ovules are attached. This is em- 

 phatically shown in the fruit of the May-apple or 

 mandrake (shown in 

 cross -section in Fig. 

 145). This point of 

 attachment is known 

 as the placenta (plu- 

 ral, placentas), 



158a. The placenta is de- 

 fined with reference to its po- 

 sition. It is evident that 

 there are two general types 

 of placentse, — those which are 

 borne upon the outward walls 

 of the ovary, and are called 

 parietal, and those that are 

 borne in the center, and are 

 called axile. Of the axile 

 placenta, there are two kinds, 

 those which are . attached to 

 the partitions or dissepiments 

 of the ovary (as in the tulip. 

 Pig. 142), and those which 

 are borne upon a separate 

 central column, 'and are, there- 

 fore, called free axile placentse 

 (as in the cockle. Fig. 143, 

 and in all the pink tribe, as 

 the pinks, carnations, chick- 

 weeds, catchflies; and also in 

 the primroses). 



159. It is now seen 

 that the pistil is not 



FiO. 143. 

 Free axile placenta of corn-cockle. 



