THE CARPEL AND OVULE 293 



the deposit of (lie pollen (Fig. 209). In some cases the style is absent, 

 as in the Buttercup or Nettle. It is a feature of variable occurrence, 

 resulting from intercalary growth which is adjustable according to the 

 proportions of the other parts. Extreme cases are seen in the Crocus 

 or in Colchicum, where the ovary is underground, while the style, 

 which is six inches or more in length, carries the stigma several inches 

 above ground, to a level a little in advance of the stamens. In the 

 Gamopetalous Dicotyledons, and in many Monocotyledons the cylin- 

 drical style is proportional in length to the tube of the corolla, as is 

 seen in Tobacco and Gloxinia, or in Lilium auratum and Narcissus. 



Fig. 215. 



Transverse section of the style of Salvia, showing the cells of the conducting 

 tissue (c) with swollen mucilaginous walls (m). (After Capus.) 



The style is sometimes traversed by an open channel, so that 

 direct access can be gained to the ovarian cavity from the stigma ; 

 this is the case in the Violet and Mignonette. But where the channel 

 is narrow it is commonly filled with a mass of mucilage derived from 

 epithelial ce*lls which clothe its surface. This is seen in the Lily and 

 Rhododendron (Fig. 225, p. 305), in both of which a separate groove 

 from each of the stigmatic lobes leads downwards to the common 

 conducting canal filled with mucilage. In other cases there is no 

 actual canal, but a column of lax tissue with mucilaginous walls tra- 

 verses the style, and serves as a conducting tissue. This is found in 

 Salvia (Fig. 215) ; also in the Corn Cockle (Agrostemma), and in the 

 Mallow. In such cases the conducting tract is connected upwards 

 with the separate stigmas, while downwards the channel branches so 

 as to lead to the several loculi of the ovary. 



