As one travels hundreds or even thousands of miles in a comfortable railway carriage and sees the same flowers growing throughout the length and breadth of the area, one cannot but wonder however the plants manage to make the journey. We know some creep along the ground, or under it, a tortoise pace, but a winning one; that some send their offspring flying away from home, like dandelions and thistles; and many others with wings and darts are blown by the wind. Berries have their seeds dropped afar by birds. Aquatic plants and those that grow beside running water travel by river and flood. European species reach our shores among the ballast. Darwin raised over sixty wild plants from seed carried in a pellet of mud taken from the leg of a partridge. So on and so on. The imagination delights to picture these floral vagabonds, each with its own clever method of getting a fresh start in the world. But by none of these methods just mentioned do the tick-trefoils spread abroad. Theirs is indeed a by hook or by crook system. The scalloped, jointed pod, where the seeds lie concealed, has minute crooked bristles, which catch in the clothing of man or beast, so that every herd of sheep, every dog, every man, woman, or child who passes through a patch of trefoils gives them a lift. After a walk through the woods and lanes of late summer and autumn, one's clothes reveal scores of tramps that have stolen a ride in the hope of being picked off and dropped amid better conditions in which to rear a family. Only the largest bees can easily "explode" the showy tick-trefoil. A bumblebee alights upon a flower, thrusts his head under the base of the standard petal, and forces apart the wing petals with his legs, in order to dislodge them from the standard. This motion causes the keel, also connected with the standard, to snap down violently, thus releasing the column within and sending upward an explosion of pollen on the under surface of the bee. Here we see the wing petals acting as triggers to discharge the flower. Depress them and up flies the fertilizing dust - once. The little gun will not "go off" twice. No nectar rewards the visitor, which usually is a pollen-collecting bee. The highly intelligent and important bumblebee has the advantage over his smaller kin in being able to discharge the pollen from both large and smaller flowers.