THE CARROT AND PARSNIP FAMILY. i53 



Bu'bon. — This has compound leaves with lobed 

 segments, the petioles being channelled above, in that 

 the two side ridges give strength to the stalk, on the 

 same principle as in " Fox's patent stays " of an 

 umbrella. They are, in fact, " flanges " of a " girder." 

 Engineers and others often imitate Nature by adopting 

 her methods of strengthening stems, etc., so that tjiey 

 can support the heavy weight of foliage and branches. 

 This is partly effected by the petiole more or less 

 sheathing the stem, thus securing a large base. In 

 palms the sheath goes completely round the stem, and 

 is made of interlacing fibres, thereby supplying great 

 strength to support the enormous weight of gigantic 

 palm-leaves. 



The flower (Fig. 63, I.) will at once be seen to have 

 an inferior ovary, upon which the five petals and five 

 stamens stand. As a rule, the calyx is either repre- 

 sented by five minute points or is wanting altogether — 

 a common occurrence when small flowers are massed 

 together. On the top of the ovary will be seen two 

 cushion-like masses or honey-discs, between which 

 arise the two short styles. The petals may often 

 have " inflected points " (I.), along which, as in a 

 little groove, the proboscis of an insect can glide so 

 as to reach the honey. 



The diagram (II.) shows the arrangement of the 

 whorls with a syncarpous pistil of two carpels, having 

 one (pendulous) ovule to each ovary-cell. 



