JCXXIV 



BOTANT. 



ovary-cavity, at last meeting in the centre, vyhen the pistil be- 

 comes multilocular with axile placentae. On the other hand, a 

 multilocular pistil sometimes becomes unilocular by the breaking 

 away of the partitions during growth. In sucli a case the pla- 

 centae form a free central column, commonly called a free cembral 

 placenta (4, Fig. XXXIII). 



In other cases a free placental column of an entirely different 

 origin occupies the axis of a unilocular but evidently polycarpel- 

 lary pistil. In Anagallis, for example, the placental column 



Fig. XXXV. 



Fia. XXXrV.— Flower of Shepherd's Purse (Capsella), with superior ovary, 

 and hypogynous stamens and perianth. 



Fio. XXXV.— Flower of waterlemon, with inferior ovary, and epigynouB 

 perianth. 



grows from the base of the ovary-cavity, and there is at no time 

 a trace of partitions. 



Adnation of the Cynoecium. — The gynoecium may be free from 

 all the other organs of the flower, which are then said to be liypogy- 

 nous, and the gynoecium itself superior (Fig. XXXIV). Sometimes 

 the growth of the broad flower-axis stops at its apex long before 

 it does so in its marginal portions; a tubular ring is thus formed, 

 carrying up calyx, corolla, and stamens, which are then said to 

 be perigyrums, and the gynoecium Imlf inferior. These terms are 

 used also in the cases where the gynoecium is similarly sur- 



