230 RECEPTION OF FLOWER-SEEKING ANIMALS AT THE FLOWER. 



are present in the centre forming a sort of fascicle which makes a useful platform 

 (c/. fig. 259). Or, again, the style or stigma may be lobed or forked, the branches 

 taking an oblique or horizontal position, thus resembling a perch (e.g. Convolvulus 

 arvensis and Siculus). Or, it may be formed by the fascicled stamens in many 

 upright, actinomorphic flowers, as in Myrtles, St. John's- Worts, the Australian 

 Acacias and various Malvaceae (at least in the fii'st stage of flowering). 



The Pinks and Scabiouses whose capitate flowers contain honey deep down are 

 preferably visited by Lepidoptera, the flowers of Umbelliferae and Euphorbiaceae, 

 whose honey is exposed and easy of access, by Flies, Wasps and other short-lipped 

 Hymenoptera. To the inflorescences of Composites and Proteaceas, the most various 

 insects are attracted, according to the form and position of the whole inflorescence 

 and the depth at which honey and pollen are to be obtained. It is impossible to 

 enumerate the various cases here for lack of space, nor, indeed, would it be desirable. 

 One more plant, Dryandra, one of the Proteacese, deserves a brief description, 

 however, on account of the remarkable form of its inflorescence. This plant is a 

 low shrub, a constituent of the Australian "Scrub ". Its flowers are arranged around 

 the margin of a cup about 4 centimetres in diameter. The bottom of the cup is 

 lined with scales only, and here collect drops of liquid secreted by the flowers, which 

 smell like sour milk. Around the margin of the cup the long styles project like 

 pins, bent slightly inwards. The pollen is collected at the tops of the styles at 

 the commencement of flowering; subsequently the stigmas are developed, ready to 

 receive pollen brought by animals from other flowers. So far as is known, this 

 arrangement of flowers and sap is not adapted to insects. It seems probable that 

 Kangaroos visit these flowers, stick their snouts into the excavated inflorescences 

 to drink up the sap, and unconsciously dust their mouths round with pollen which 

 is subsequently conveyed to the stigmas. The respective heights of the Dryandra 

 bushes and of Kangaroos, and the configuration of the inflorescence compared with 

 the snout of this animal, render the assumption a not impossible one. 



The efiicacy of all these arrangements for promoting the quick and easy obtaining 

 of food from flowers by " bidden guests " is obviously much enhanced by the exis- 

 tence of others for the exclusion of hurtful and undesired visitants. As hurtful 

 may be characterized all such animals whose visits interfere with or prevent the 

 speedy transfer of pollen from flower to flower. Such are small wingless animals 

 which must of necessity reach the honey and pollen on foot. Let us consider the case 

 of one of these little pedestrians. Suppose it to have reached a flower and covered 

 itself with pollen; it has now before it, in order to transfer this pollen to a stigma 

 on another plant, a long and toilsome journey beset with dangers for the pollen, 

 quite apart from the length of time taken. The pollen may be so easily rubbed ofl" 

 on the journey by hairs and other structures encountered, or it may be washed off" 

 by rain. Then, even if a second flower be attained, what are the probabilities of its 

 being in a receptive condition? How otherwise it is with the lightly-flying insects 

 and humming-birds! They dart from plant to plant with extraordinary rapidity 

 and visit half-a-dozen flowers within a minute or so, thus transferring the pollen 



