FLOWERS AND INSECTS 235 



and colour has to do with the fertilization of its 

 ovules, and in general to discourage pollination from 

 its own anthers, and encourage that from other flowers, 

 (of the same species), though self-fertilization is often 

 provided for in case the other fails. 



Thus the stigma and anthers usually come to ma- 

 turity at different times the former being in wind- 

 fertilized plants the first to ripen, and the last in those 

 visited by insects, as may be seen in the flower head 

 of a Sunflower (see Part II). 



Wind-fertilized flowers differ also from those which 

 depend on the visits of insects, in having, as a rule, 

 light powdery pollen, which is easily carried by the 

 breeze, and long feathery styles. This is the case 

 with SORGHUM, Wheat and other grasses. 



In many animal pollinated flowers the object ap- 

 pears to be to discourage all but a particular class of 

 insect or bird. Thus some flowers are adapted specially 

 for the visits of long-tongued insects (butterflies and 

 moths), their long tubular corollas preventing smaller 

 insects reaching the honey that lies at the bottom. 

 Others are flat so that the honey is freely exposed, 

 and are visited mostly by flies and beetles with short 

 tongues. Some flowers are closed in, and can be 

 opened only by clever or heavy bodied insects, such 

 as bees. This is the case with the Pea and other 

 PAPILIONACE.E, with ANTIRRHINUM (the Snapdragon) 

 and many others. Flowers which open at night, like 

 MILLINGTONIA (the Indian Cork-tree) and IPOMCEA 

 BONA-NOX (the Moon-flower) are usually white, and have 

 heavy sweet scents, so as to be easily found by night- 

 flying moths. Others again have like ARISTOLOCHIA 



