120 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The first result of such adaptation is that the sepals (as in the Pink), 

 the petals (of the Foxglove), or both of these (in the Primrose), become 

 coherent into tubes. Their tise is, first, to furnish a strong support for an 

 insect alighting on the expanded " limb " of the corolla, as of a Primrose, 

 or more or less crawling inside, as of a Foxglove. 



Secondly, it extracts the honey secreted by glands at the base ; as is 

 well known to any one who has sucked the tube of a corolla extracted 

 from the flower of the Deadnettle. 



This tube may be imitated, but without any cohesion having taken 

 place, as in the Wallflower ; in which the four sepals overlap one another 

 in pairs, and, being rigid, they are strong enough to support the slender 

 " claws " or stalks of the petals, as well as the weight of the insect 

 alighting upon their expanded limb. 



In a Pink the sepals are coherent, but the petals are of the same form 

 as those of the Wallflower, in having slender claws and an expanded limb ; 

 but in a Primrose the claws of the petals have united, and so form a 

 slender tube within that of the calyx. If the corolla-tube is sufficiently 

 strong to carry the insect, it does not require the extra support of a calyx- 

 tube, so the sepals remain free, as in the Foxglove. 



The next effect of floral irritation is the production of honey-glands 

 and other growths of the floral receptacle itself. 



The extremity of the flower- stalk is usually somewhat enlarged in 

 order to carry all the parts of the flower ; it can be much more enlarged 

 under such a stimulating process as cultivation, as we see in the fruit of a 

 Strawberry (fig. 45) ; the succulent edible portion being simply an 

 enormously increased apex of the floral receptacle, which carries the seed- 

 like carpels, or achenes, only. 



Besides this, the receptacle can extend horizontally (fig. 45), and so 

 form a platform or ledge round the base of the flower. The object is to 

 secrete honey. This is particularly well seen in the Raspberry ; and is 

 very attractive to bees, which suck up the honey from the circular trough 

 with great avidity. This, together with the honey, is regarded as being 

 the result of the actual visits of the insects themselves. 



The effect resulting from this lateral expansion of the receptacle is to 

 push out the calyx, corolla, and stamens to a little distance from the centre, 

 where the pistil remains, as shown in the Strawberry (fig. 45). 



This condition of the petals and stamens was called " perigynous," 

 which means around the pistil. In a Buttercup, where there is no such 

 lateral expansion of the receptacle (inasmuch as the petals supply the 

 honey), the petals and stamens arise from the receptacle immediately 



EiG. 46. — Vertical section of flower of 

 Apricot ; ^9, petal ; ou, ovary of pistil, 

 in centre of, tc, the receptacular tube. 



Fig. 47. — Vertical section of flower of 

 Rose ; re, receptacular tube ; ou, 

 ovaries of free carpels within the 

 tube ; sty, styles of carpels. 



