140 THE ROMANCE OF SEED-SOWING. 



Switzerland, and is by no means rare in the Tyrol, carried to 

 these districts by Birds. 



Animals act as dispersers unconsciously, as I have already 

 said. Many fruits possess hooked processes in the shape of 

 curved hairs, or spines, or prickles. These become entangled in 

 the wool or fur of Sheep, Cows, and other animals, and are thus 

 effectually carried away. Of these, examples are seen in Wild 

 Carrot, Bur-parsley, Hedge-parsley, Burdock, Agrimony, Avens, 

 Enchanter's Nightshade, Hound's-tongue, Cleavers or Goose-grass 

 (familiar to everyone who has clambered through a hedge), and 

 some Forget-me-nots. In Burdock, the hooks are on the scales 

 of the involucre surrounding the flowers, so that one hook 

 being caught carries away several fruits, which further, each 

 possess a pappus. No wonder we find Burdock everywhere. 

 Some seeds themselves are similarly hooked — the large Stitch- 

 wort, for example, which decks nearly every hedge-bank in April. 



Some foreign genera, such as the Mexican Alartynia, or 

 Devil's Claws, possess horns three or four inches long, and 

 Marty7iia well merits its name by the way in which it attaches 

 itself to horses' tails and irritates the innocent proprietors. 

 Others, like Pliwibago rosea, are viscid, and stick to animals by 

 this means. In Afyzodendron, a South American parasite, whose 

 brilliant flowers and fruits brighten the dark Patagonian forests, 

 the fruits are provided with three long, feathery, viscid appen- 

 dages, and, either carried by Birds, or wafted by breezes, to some 

 tree, they fasten themselves to a twig until germination ensues, 

 and then grow up into plants, feeding on the juices of the tree, 

 where they have taken lodging and board without so much as 

 " by your leave." 



IV. — Rupture. — By this I mean the various methods by 

 which seed-vessels — i.e., fruits — dehisce, or open, of their own 

 accord, either in part, when the wind usually shakes the seeds out, 

 or through their entire length, in which cases the contained seeds 

 are more or less forcibly expelled. In this latter case, there is 

 complete self-dispersion, whereas in the former, the opening of the 

 vessel is the only part of the process entirely performed by the 

 plant. Let us first glance at a few cases of complete self-dis- 

 persion. 



