520 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



now enters a complete filament and anther, so that, instead of five or other- 

 number of stamens, these may be multiplied, as occurs in Hypericum and 

 'Malvaceae. 



When flowers are in whorls of twos or fours, the usual interpretation 

 is that such have arisen from opposite leaves. This is well seen in 

 members of the Oleaceos, as Lilac, Privet, Ash, &c. 



The Tormentil, however, has normally only a 4-petalled corolla, but 

 occasionally there are five petals. This may be explained by this plant 

 habitually living in a poor soil as of heaths, so that the number four has 

 become a fixed character in this species of Potentilla. 



Freedom and Union. — As leaves grow out separately from a shoot, 

 so originally were all members of floral whorls free. But, from certain 

 exigencies, the parts of any whorls may be united or ''cohere " together. 

 This cohesion is pre-eminently required for insect pollination, as will be 

 explained hereafter. 



Thus the five sepals of a Carnation or Primrose form a " cup " ; hence 

 the term calyx, the Latin for "cup." Similarly are the petals often 

 united in flowers, as of the Primrose, Foxglove, Potato, &c. 



In the Furze there are ten stamens with narrow flat filaments which 

 cohere, edge to edge, making a tube ; but the anthers are free ; whereas 

 in Composites the reverse takes place, the filaments being free and the 

 anthers coherent into a tube. 



With regard to the pistil, it is by far the most general rule for it to 

 be composed of two or more carpels coherent into one body, as of a Wall- 

 flower with two carpels, a Poppy with several, &c. 



The Floral Beceptacle. — The end of the flower-stalk, or floral 

 receptacle, plays an important part in flowers. As the parts of a flower 

 are much crowded, the extremity usually enlarges to carry them. This 

 enlargement is well seen in a Strawberry, as it is the structure we eat. 

 It is the " cone " inside a Raspberry and Buttercup. In all three the use 

 is to carry the immense number of separate or free carpels. 



Besides enlarging upwards, the end of the flower- stalk may spread 

 out horizontally and form a sort of dish or groove round the pistil. Such 

 is well seen in the flower of the Raspberry, and its use or function will be 

 discovered to be the secretion of honey. 



A further development takes place when the edges of the "dish " grow 

 upwards and form a "cup" or "tube." Such occurs in the Cherry and 

 Rose. The result is that while the carpels (single in the Cherry, but 

 many in the Rose) remain below at the bottom and sides of the cup, the 

 sepals, petals, and stamens are carried up and borne on the rim. 



In the Cherry and Plum this cup or " receptacular tube," as it is 

 called, disarticulates below and leaves the fruit to grow and ripen by itself. 

 In the Rose the tube is persistent, and forms the "hep," full of free carpels 

 (achenos), within it. 



hi many flowers an "adhesion" takes place during growth, between 

 the receptacular tube and the ovary or ovaries. Thus, in the May with 

 1 or 2 carpels, in the Apple and Pear with 5, when these fruits are cut 

 across the\ arc found to be welded into the thick, fleshy, superficial tissue 

 of the cup or tube. 



To explain this we must remember that the tube, if free, as of the 



