408 ORDER GERANIACE^, OR GERANIUM TRIBE. 



also five in number, except in a few instances in which one is 

 undeveloped ; their veins are unusually prominent, and they give 

 to the petals a streaked or pencilled appearance. These veins 

 consist almost exclusively of air-vessels, and they serve as 

 beautiful objects of microscopic investigation. The stamens are 

 usually two or three times the number of the petals ; in the 

 Geraniums there are ten, and they distinctly form two rows, of 

 which the outer one is shorter than the other ; and in the Ero- 

 dium or Cranesbill, also a British genus, the stamens of the outer 

 row do not bear anthers. In the cultivated Geraniums, or Pelar- 

 goniums, the corolla is somewhat irregular, the two upper petals 

 being larger than the three lower, and standing apart, so as to 

 give the flower the appearance of having two lips. The pistil of 

 the Geranium tribe has a singular structure. It consists of five 

 carpels clustered together round an axis, which is the disk pro- 

 longed upwards through their centre in each cell of the ovarium 

 is a single seed. The styles adhere together in such a manner as 

 to form but a single column, divided at the top into five lobes, 

 which are the stigmas. (Fig- 151). 



573. When the fruit is ripe, it resembles in a striking manner 

 the bill of certain birds ; whence the British Geraniums are 

 known by the name of Cranesbill ; and the Erodium (an allied 

 genus) by that of Storksbill. This singular appearance is owing 

 to a very simple circumstance. In most plants, the styles shrink 

 up or fall off, at the same time that the flower fades ; and, by 

 the time the fruit is ripe, they have entirely disappeared. But 

 in the Geranium the styles continue to grow and harden as fast 

 as the fruit itself; and when the latter is ripe, the styles project 

 from the ovaries in the form of a beak. At the time that the 

 fruit is ripe, the seeds are sown in a very curious manner. The 

 carpels and styles are still clustered together round the central 

 axis ; but the latter shorten in drying ; and as they adhere so 

 closely at their points that they cannot separate there, they 

 actually cause the separation of the carpels at their base ; and 

 these, when torn up as it were by the roots, curve towards the 

 top of the style, and at the same time open by the face which 

 was previously adherent, so as to let the seed drop out. This 



