DISPERSAL BY ANIMALS. 867 



dragged by ants under the ground, or into crevices in walls, germinate in those 

 situations in the following year. It sometimes happens also that here and there a 

 seed is left behind on the route of the ants, and in that case the caruncle is usually 

 eaten off. Such abandoned seeds likewise germinate in the following year, and this 

 explains the fact that the routes traversed by ants are regularly planted with 

 certain species of plants. For example, in the Botanic Gardens at Vienna, the 

 presence of Ghelidonium majus is a constant feature of the ant-runs. 



The transport of fruits and seeds to spots more or less remote from the localities 

 where the mother-plants grow, by animals which have a definite purpose in view 

 in so conveying them from one place to another, is on the whole a rare means of 

 dissemination, and is confined to comparatively few species. But the unintentional 

 dispersion of fruits and seeds by animals is of much more common occurrence. 

 The objects thus dispersed get stuck or hooked, or otherwise fastened to the animals 

 in the course of the latter's wanderings, and sooner or later are got rid of by them 

 as being an unpleasant encumbrance. The places where such fruits and seeds are 

 deposited are, however, always more or less distant from the spot where they 

 ripened, and, as a general rule, they afford favourable conditions for germination. 



The adhesion of fruits and seeds to the feathers of birds and to the skin or fur 

 of other animals is due either to the agency of water, mud, and moist earth, or to 

 that of special sticky substances secreted by the plants. In the case of many 

 aquatic and marsh plants, such as [the genera Alisma, Butomus, Carex, Myriophyl- 

 lum, Phellandrium, Polygonum, Potamogeton, Sagittaria, and Sparganiwin, the 

 fruits and seeds are unprovided either with special organs of attachment or with 

 viscid secretions, but as was mentioned on p. 847 they have the power of keeping 

 afloat on the surface of the water. If one dips one's hand into a pond covered with 

 floating fruits of this kind, and draws it out again quickly, a number of the fruits 

 always adhere to the skin by means of drops of water. The same thing happens 

 when water-fowl rise from the water after swimming about for a time. The beak, 

 legs, and feathers of a bird that has been shot not infrequently have the fruits in 

 question clinging to them after the water has run off. If the bird had settled upon 

 another pond the fruits would no doubt have been transferred to it. Adhesion 

 through the intervention of water is assuredly by no means an insignificant factor 

 in the dispersion of fruits to moderate distances. 



The agency of mud and wet, boggy earth in affixing objects to animals is espe- 

 cially efiicacious in the case of the numerous small fruits and seeds, which are by 

 this means caused to adhere to birds when they come to the water's edge to drink. 

 Jackdaws, herons, and snipe are not very particular about cleanliness, and they are 

 invariably found to be smeared with mud. Swallows, particularly the rough-footed 

 species, are very important members of this category, as during their sojourn on the 

 banks of rivers and ponds they get bespattered with particles of mud. It is true 

 that they try to cleanse themselves from all such foreign matter, but when the 

 season for migration approaches they become restless and excited and forget the 

 morning toilet which, until then, is performed with great care. In the same manner 



