RECEPTION OF FLOWER-SEEKING ANIMALS AT THE FLOWER. 



223 



from plant to plant is accomplished with certainty and despatch; it may be said 

 of these hanging bell-flowers that they are directed towards the side from which 

 the most welcome of all guests will reach them. Nor must it be forgotten that 

 from this pendent position accrue many other advantages; thus the pollen is well 

 protected fi-om wet by the corolla (c/. p. 118), and numerous little Hymenoptera, 

 useful in carrying pollen, use these bells as night-quarters {cf. p. 163). 



In a large number of plants, though the closed buds are directed upwards, the 



Fig. 256.— Preparation of Flowers for Insect-visits in the Labumuiu {Cytisus Laburnum). 

 J Erect raceme ; all the flowers still closed. 2 pendent raceme ; some of the flowers open. 



flower-stalks bend down on opening, so that the entrance to the flower is directed 

 sideways. When, at length, insect-visits are no further required, the older flowers 

 collapse and point downwards. This change in the direction of the flower may be 

 well observed in Honeysuckle (Lonicera), Evening Primrose {(Enothera), Acanthus, 

 in Balsams (Impatiens), Galega, Melilotus, and many of the Clovers (Trifolium, cf. 

 fig. 252 9 p. 184). 



Very peculiar is the behaviour in a number of Papilionacese, of which the 

 Laburnum {Cytisus Laburnum) may be taken as type (cf. fig. 256). The axis of 

 the raceme remains erect so long as all the flowers of the inflorescence are in bud, 

 the individual flowers being so placed that the standard is above and the keel 



