GAMOPETAL^— SCROPHULARIACE^ 157 



than the other two; the medium posterior stamen is absent 

 (see Labiatae for method of proof); anthers inclined together 

 in pairs, and with divergent lobes. Disk (n) forms a ring round 

 the base of the ovary; it is a nectary. Carpels two, syncarpous, 

 superior. Ovary {ov) two-chambered, with numerous ovules on 

 an axile placenta. Style {sy) one. Stigma two-lobed. The 

 ..ps 



Fig, 193. — Vertical section of flower of 

 Foxglove. 



Fig. 194, — Floral diagram 

 of Foxglove. 



carpels are median in position. Fruit (fig. 123) a two-valved 

 capsule, leaving the numerous seeds attached to the thick axile 

 placenta (j>l). Pollination. — The stamens dehisce before the 

 gynaecium is ripe : that is, the flower is proterandrous. The 

 flowers are cross-pollinated by the agency of humble-bees only. 

 The humble-bee creeps bodily into the flower (we notice that it 

 just fits the flower), and its back comes into contact with the 

 stigma-lobes and anthers. Thus, as in the Dead Nettle, the 

 pollen is conveyed from flower to flower on the back of the bee. 



THE SUPPRESSION OF STAMENS in the Scrophulariace^. 



The androecium of different Scrophulariacese is interesting in 

 showing the gradual suppression of special stamens. The Mullein 

 {Verbascum) has a nearly regular flower with five stamens, 

 which alternate with the five petals (fig. 195). The Snapdragon 



