EARLY SUMMER FLOWERS 187 



and relative positions of all the parts, an intact flower should 

 be taken and the relation of the parts when undisturbed 

 carefully considered. We have seen that the nectar is to be 

 found at the base of the corolla-tube, protected by a ring of hairs. 

 The curved style lies against the posterior lip, and the stigma, 

 which at first is closed, projects beyond the anthers. The elon- 

 gated connective is balanced on the end of the filament, so that 

 the two fertile anthers lie side by side beneath the posterior lip, 

 while the sterile knobs stand right in the path leading to the 

 nectar. Each connective thus forms a lever balanced on the 

 filament, the shorter arm of the lever bearing the sterile knob. 

 If now an insect such as a bee alights on the lower lip and, insert- 

 ing its head, passes its proboscis down to the nectar, it is easy 

 to understand what will happen. The downwardly directed 

 halves of the anther will be pressed upwards out of the way, and 

 this will cause the other arms of the levers to descend. This 

 movement will bring the pollen-containing half of the anther in 

 contact with the insect's back, and pollen will thus be deposited 

 on the latter. The action of the insect can be imitated by passing 

 a needle or bristle into the corolla. 



In older flowers, that will have already shed their pollen, 

 we find that the style has grown longer and its tip has curved 

 down. The two lobes of the stigma now gape apart, and are 

 ready to receive pollen on their inner faces. If a bee, which has 

 had pollen deposited on its back in visiting another flower, comes 

 to a flower in this later stage, the stigma will brush against the 

 region of its back on which the pollen was placed. The flower 

 will thus be cross-pollinated. 



The flower of the Sage is a highly specialised arrangement 

 for ensuring cross-pollination by the agency of bees visiting the 

 flower for nectar. In correspondence with the precision of the 

 mechanism, we find that the amount of pollen needed is reduced. 

 As compared with the Dead-nettle, two stamens have become 

 functionless, and only one half of the anther in each of the other 

 two forms pollen. Other species of Salvia cultivated in the 

 flower garden will show even more specialised arrangements for 

 pollination on the same principle. 



The fruit consists of four nutlets, each developed from one 



