82 



CARPELS. 



Fig. 111. 



PISTIL. 



completely to each other. When the carpels remain entirely 



separate from each other, they constitute several distinct pistils, 



and when they are united into one mass, they form what is ordi- 



narily called a single pistil. Sometimes this coherence 



takes place through the whole length of the carpels, 



sometimes in the ovaries, without the styles partici- 



pating, so that the single mass formed by the ovaries, 



and ordinarily called a single ovary, is surmounted 



by two or more styles ; and when the styles are united, 



the stigmas of the different carpels may be separate 



(Jig- HO), or they may cohere (Jig- 104). 



52. The number of cells we find in an ovary when 

 we cut through the lower part of a pistil, depends upon 

 the number of carpels that are united together: some- 

 times there is but one, at other times two, three, four, five, or 

 even more. Its general form is commonly ovoid (egg-shaped). 

 Finally, the cell of each carpel encloses one or more ovules, 

 which, by being developed, become seeds. 



58. The relations of the ovary with 

 other parts of the flower vary, and fur- 

 nish important characters for the classi- 

 fication of plants. Sometimes the base 

 of this organ corresponds to the point 

 at which both the stamens and perianth 

 are inserted, so that the ovary is free 

 at the bottom of the flower ; it is then 

 termed a super -ovary {Jig. 

 112). At other times it is uni- 

 ted entirely round the tube of 

 the perianth, so as to form one 

 body with the calyx, and is 

 only free at its upper part ; in 

 this case the stamens and petals 

 seem to arise above the ovary, 

 and is said to be infra (below), 

 or adherent (fg. 113). This latter 

 arrangement carries with it the coherence 

 of the sepals to each other : therefore 

 whenever the ovary is infra, the caly* 

 Fig. 113. NARCISSUS. is necessarily monose'palous. 



PISTIL. 



Explanation of Fig. 1 1 1 .The pistil :- 

 the style ; </, the stigma. 



r, the torus ; 6, the ovary ;- 



52. Upon what does the number of cells in the ovary depend ? What dc 

 the cells of the carpels contain / 



53. What is a super-ovary ! What is an infra-ovary ? 



