The Small-flowered Crane's-bill (_G. pusillum_) also resembles the Dove's-foot Crane's-bill, but its flowers are usually smaller--about a third of an inch in diameter--and of a pale lilac colour. The stems are prostrate and downy, from six to eighteen inches long; and the leaves roundish and deeply lobed. The sepals terminate in a sharp point, and the petals are notched. This is a very common species, which flowers throughout the summer. British wild flowers of the Geranium family are divided into two groups, known popularly as the Crane's-bills and the Stork's-bills, the former constituting the genus _Geranium_, of which several flowers have been described; and the latter forming the genus _Erodium_. These two groups are sometimes confused by young botanists, but may be easily distinguished by the aid of the following notes:--The flowers of the Crane's-bills are symmetrical, while the petals of the Stork's-bills are rather unequal in size and sometimes deficient. In the former there are ten stamens, five of which are alternately larger, as previously mentioned; while the latter have five perfect stamens, glandular at their bases, and five alternating, abortive ones. Further, in the genus _Geranium_ the persistent styles are straight, while in the Stork's-bills they are twisted spirally. [Illustration: THE BLOODY CRANE'S-BILL.] The manner in which the seeds of Stork's-bills are dispersed is particularly interesting:--When the fruit is ripe the carpels separate, and the twisted styles are gradually released from one another, from below upwards, till the fruit is finally set free and blown away by the wind. The carpels thus detached are each furnished with a long style, the lower portion of which is coiled like a corkscrew, while the upper part is straighter but bent to one side. Now, these styles are hygroscopic--that is, they are influenced by changes in the condition of the atmosphere as regards moisture. This may easily be shown by placing the fruit in an upright position on a piece of white card, and fixing it so with a little spot of glue or gum, so that the bent upper end of the style is free and serves as a little pointer. If now the open mouth be placed close over the carpel, and moist air be breathed upon it, the corkscrew will partially uncoil, causing the pointer to turn; and as the carpel dries again the pointer will resume its former position.