STRUCTURE OP OVARIUM AND FLOWER. 



281 



apart. The position of the pips or seeds of the Orange, will give 



a good idea of the manner in which they are usually situated 



within the carpels, especially when they are few in number. 



Sometimes, ho we ver, they are attached to the 



whole length of the carpel, from one end to 



the other, as is seen in the common Pea, of 



which each pod is a separate carpel. The 



portion of the carpel from which the ovules 



arise, is usually thick and fleshy, and is 



termed the placenta. The section of the 



pistil of the Whortleberry -, (Fig. 82) will 



give an idea of the arrangement of the 



parts in an ovarium, whose carpels and 



styles have united. The ovarium , of this 



flower is wrapped over by the leafy portion 



of the flower itself; which is seen to rise 



beyond it at b. The centre of the ovarium 



is occupied by a thick fleshy placenta, 



formed by the union of that of the several 



carpels ; and on this the ovules are 



clustered. Above is seen the signal style PIG. 82. PISTIL OF VAC- 



with its stigma. Another variety of the M j 



same kind of structure, is shown in Fig. 83 ; centa ; e, ovules;'/, pistil; 



i i 7 1*1 &n<l o stiijrrnjv. 



here the ovarium, o, is in like manner 



enveloped by the outer part 

 of the flower, a ; and the par- 

 titions between the carpels 

 have entirely disappeared, so 

 that the only one central pillar 

 is left, around which the 

 ovules are clustered. There 

 is another common form of 



^ OVarium > of which that 

 of the Pansy Or Heartsease, 



Fig. 84, may be taken as 

 an example : in this, the partitions have disappeared ; but the 

 placenta? of the several carpels, instead of remaining clustered 



PIG. 83.-OVARIUM OP THAMNKA UNI- 

 FLORA; a, calyx; b, ovarium ; c, disk; d, 



