300 THE FLOWER. 



which are occasionally developed on the margins of leaves (as in 

 the well-known case of Bryophyllum, Fig. 271). Since both 

 margins of the infolded leaf may bear ovules, the latter are nor- 

 mally arranged in two rows (one for each margin) on the inner 

 or ventral suture ; as is seen in Fig. 263, 374, 377. The ovule- 

 bearing portion of the ventral suture, which often forms a ridge or 

 crest projecting more or less into the cavity of the ovary "is named 



543. The Placenta, As it corresponds with the ventral suture, 

 and is in fact a part of it, or a cellular growth from it, it is always 

 placed next the axis of the flower ; as is evidently the case when 

 two, three, or more pistils are present (Fig. 379 - 383). Each pla- 

 centa necessarily consists of two parts, one belonging to each of 

 the confluent margins of the transformed leaf. It therefore is fre- 

 quently two-lobed, or of two diverging lamella? (Fig. 263). The 

 ovules vary greatly in number ; being sometimes very numerous 

 and in several rows on a broad placenta, as in the May- Apple 

 (Podophyllum) ; sometimes in two normal rows occupying the 

 whole length of the ventral suture, as in the Larkspur, Columbine, 

 Acta3a (Fig. 377), &c. ; sometimes reduced to one row in appear- 

 ance, as in the Pea, where on inspection they will be found, how- 

 ever, to be alternately attached to each lamella of the placenta, that 

 is, to each margin of the leaf: again, they occupy only its middle, 

 base, or summit, where they are often reduced to a definite num- 

 ber, to a single pair (Fig. 375), or to a single one (Fig. 316). 



544. When the pistils are distinct or uncombined, they are said 

 to be apocarpous ; when they are united, and form a compound 

 pistil, they are sync'arpous. We have carefully to distinguish be- 

 tween the simple pistil, which represents a single member of the 

 gynsecium (419), and the compound pistil, which answers to the 

 whole circle coalescent into one body. To subserve this purpose, 

 botanists have coined the name of 



545. The Carpel or Carpidium, This name designates an individual 

 member of the gynsecial circle, whether it occur as a separate or 

 simple pistil, or as one of the elements of a compound pistil. It is 

 in the latter case that the name is principally needful. All degrees 

 of union of the carpels may be observed, from the mere cohesion 

 of their contiguous inner angles, to the perfect consolidation of the 

 ovaries while the styles remain distinct, as in Spergularia (Fig. 

 387), or of the latter also. Rarely the stigmas or styles are united 

 while the ovaries remain distinct, as in Asclepias and Apocynum 



