1900] ENTOMOLOGICAL SOCIETY. 31 



Of the importance of cross-pollinatioa — i. e. of fertilization with pollen from other 

 blooms of the same sort, we may jadge from the arrangements made in nature to secure it. 



(1) First we notice th3 woaderful abundance of the pollen — sufficient for every 

 requirement. Take your stand by an apiary towards evening, and watch the returning 

 bees. How laden they are with bee-bread — which is compressed pollen — and yet in the 

 course of their operations they have been instrumental in fertilizing thousands of blossoms. 

 Yes, the busy workers have discharged their duties, and have not been stinted in their 

 reward. 



(2) We find that the various arrangements of the floral leaves, or perianth, for the 

 shelter and preservation of the pollen are worthy of observation. Take that common 

 flower the Dandelion {Taraxacum officinale). This flower 13 in reality an inflorescense 

 consisting of a hundred or more flowerets packed together. This collection of small 

 blossoms is surrounded by a green involucre — the whole forming a capitulum which 

 closes tight on the approach of rain. 



In the Sun-flower (Relianthus annuus), the capitulum bends over in wet weather ; 

 and the moisture is shed from the roof-shaped receptacle and the sheltering disk flowers. 



In many of the lilies, the corolla forms a bell-shaped roof under which the re-produc- 

 tive organs lie in safety ; and in the snapdragon and other flowers of like structure they 

 are shut up as in a cabinet — a cabinet which the bees know how to open. 



(3) We learn that the relative positions of the various organs in many instances 

 render self-pollination impossible. 



The English Primrose [Primula vulgaris) aflfords us an instance of this. The 

 flowers of the primrose are of two kinds. In one the style rises higher than the stamens, 

 in the other the stamens are placed above the style. In either case the stisimas are at the 

 same height as the anthers in the other. An insect comes to a flower which has a long 

 style ; its proboscis at a certain part is charged with pollen from the elevated anthers of 

 a blossom which it has just left. As the insect rifles the long-styled flower of its sweets 

 this pollen is brought in contact with the stigma which is at the right height to receive 

 it. At the same time the proboscis of the insect is acquiring a fresh sapply of pollen 

 lower down irom the short anthers and this it will convey to the next short-styled prim- 

 rose blossom that it visits. It is possible that the short-styled flower may be self-pollin- 

 ated •; but it is quite impossible that the long-styled flower can be so. 



(4) We see that the ripening at different times of the anthers and stigmas of sooie 

 kinds of b ossoms insures, with the aid of insects, the cross-fertil zation of blossoms. 



The Monk's hood [Aconitum napellus) affords us an example of this. The blue 

 flower of the monk's-hood is really the calyx. Its uppermost sepal forms a sheltering hood 

 in which the two posterior petals are hidden. These petals are of a remarkable shape, 

 curved and clawed, and they secrete nectar which attracts the humble bees. The monk's- 

 hood is exclusively a humble-bee flower. The other petals are either wanting or are 

 insignificant. In a newly opened monk's-hood flower the numerous stamens protrude and 

 their anthers ripen before the stigmas. A humble-bee alights in the middle of the 

 flower, holding on by the side sepals. In its struggles to reach the nectaries, the under 

 part of its body is brought in contact with the anthers and becomes charged with pollen. 



In the older blossoms of the monk's-hood the stamens all bend back out of the way, 

 and the carpels are protruded. A bee alighting on such a blossom brings pollen to the 

 stigmas now ready to receive it and the blossom is fertilized. 



Another noteworthy instance of a plant which ripens its anthers and stigrnas at 

 different times is afforded by the Foxglove [Digitalis purpurea). The foxglove like the 

 monk's-hood is a humble-bee flower. Indeed its form and size seem especially adapted 

 for the reception of the humble-bee. The stamens and pistil are extended along the 

 upper part of its inner surface. A humble-bee backing out, after sucking the nectar 

 from the further recesses of the flower, scrapes off, by means of its bristly coat, the pollen 

 from the anthers, and carries it on its back to other foxglove blossoms whose stigmas are 

 ready to deceive it. 



The result of cross-fertilization seems to be the production of more numerous and 

 finer seed, and eventually of stronger and more beautiful plants. 



Some flowers have a wide circle of insect attendants. The Buttercup is known to 

 be visited by more than sixty different kinds of insects (Percy Groom's Elementary 

 Botany, page 121). Others are exclusive, permitting only the viiits of a favoured few. 



