292 



THE STKUCTURE OF FLOWERS. 



I have also found the sepals ovuliferous in a monstrous 

 orm of Violet, which was almost entirely virescent (Fig. 71). 



Progeessive Changes of the Corolla. — For petals to 

 become staminoid is far from uncommon. It is a normal con- 

 dition in Atragene (Fig. 44, p. 141), which illustrates the 

 transition, and in' Water-lilies, where a gradual development 

 of the anther cells is accompanied bj a gradual reduction of 

 the petal to a filament. As abnormal instances may be men- 

 tioned, a case of Foxglove which I have elsewhere * described 

 as having the corolla split up into strap-shaped antheriferous 

 processes (Fig. 72), and a Columbine in which the spurs 



Fig. 70.— Calyx of Garden Pea, 

 with carpellary lobes (after 

 Masters). 



Fig. 71.— Ovuliferous 

 sepal of Violet. 



Fig. 72.— Corolla of Fox- 

 glove, with staminate 

 tube. 



became curiously coiled and bore pollen within the tissue of 

 the coils (Fig. 73). 



Pistiloid petals are of rare occurrence. As an example is 

 Begonia (Fig. 74, a), in which the apex of the petal was 

 green and stigmatiform, the basal part being broad, coloured, 

 and ovuliferous. Fig. 74, h, shows a petal, ovuliferous below, 

 stigmatiferous at the summit, and antheriferous midway ; 

 c is a rudimentary ovule. 



Progressive Changes in the Stamens.: — The only change 

 * Journ. Linn. Soc. Bot., vol. xv., p. 86, tab. 3. 



