ANGIOSPERMS. 



379 



the style is formed from the upper part of the young carpel, it may come to be 

 placed on the axile side of the monomerous ovary, if the carpel bulges out con- 

 siderably owing to the stronger growth of the ovary on its dorsal side, as in Fragaria 

 and Alchemilla\ if this happens to the individual carpels of a polymerous ovary, 

 the ovary itself appears to be depressed in its centre, and the style rises from out 

 of the depression (Fig. 304, 305). The same thing occurs in the Labiatae and 

 Boragineae in an exaggerated form, where the four lobes of the bicarpellary ovary 

 bulge out very strongly above (Fig. 307 A, }, so that the style at length appears 

 to rise from between four parts of the ovary which seem almost entirely unconnected, 

 and is known as a gynobasic style. 



FIG. 310. Development of the flower of Helianthits 

 annuls, the numerals from / to VII show successive stages 

 (IV and VI have been transposed by mistake) ; c corolla, / 

 calyx.y filaments of the stamens, a their anthers, x the basal 

 portion which becomes later the lower part of the corolla-tube 

 bearing the epipetalous stain ens, fK the inferior ovary, SK 

 the ovule, k the carpel, gr the style. 



FIG. 311. Development of the flower of Calanthe veratrifolia 

 in successive stages from A\.oB. A and C seen from above, B and 

 D in longitudinal section; s the sepals, p the petals, pi the petal 

 which developes into the lower lip, of the single fertile anther, ae 

 and at abortive anthers of the outer and inner circle ; asm B denotes 

 the sterile stamens, ep in D one of the three carpels. After Payer. 



The style may be hollow, that is, may be traversed by a longitudinal canal which 

 is a narrow continuation of the cavity of the ovary, as in Butomus (Fig. 299 B, F] 

 where the canal is open up to the hairy surface of the stigma, and in Viola (Fig. 312) 

 in the same way, where it is broad and ends in the round open cavity of the stigma ; 

 in Agave also and in Fourcroya the style is hollow along its whole length and open 

 at the stigma, but the canal divides below into three branches which run into the 

 loculi of the ovary, an arrangement which occurs also in other Liliaceae ; sometimes 

 the style is hollow at first, as in Anagallis (Fig. 309 ), and is afterwards filled up by 

 the growth of the tissue. But in most cases there is no open passage to be found 

 in the style of the mature gynaeceum, or at any rate not in its upper portion, but 

 it is filled with a loose tissue, the conducting tissue*, in which the pollen-tubes grow 



See on p. 403. A description of this tissue will be found on a subsequent page. 



