THE CARPEL AND OVULE 257 



the deposit of the pollen (Fig. 1S7). 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 awatum and Narcissus. 



.0 





J cm 



^^^ o 



C/Ooo ® 



000 ®® "r@«'®@( 



Fig. 205. 



Transverse section of the style of Salvia, sliowing 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 cells which clothe its surface. This is seen in the Lily and 

 Rhododendron, 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 traverses the style, 

 and serves as a conducting tissue. This is found in Salvia (Fig. 205) ; 

 also in the Corn Cockle (Agrostenuna), 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. 



