THEIR PLACE IN NATURE 17 



among species like the woodcock and marsh birds 

 which live in muddy areas. Darwin was able to 

 rear eighty-two plants from a single ball of earth 

 adhering to the foot of a partridge. The rough- 

 ened shank of the large tinamou of South America 

 carries an appreciable amount of earthy material 

 lodged in the crevices of its rear scales. This 

 forest mold ordinarily contains seeds. 



Birds are beneficial to vegetation in other ways. 

 The hummingbird, for instance, aids in the cross- 

 pollination of blossoms by carrying pollen in its 

 feathers from one flower to another. This holds 

 true for other species, but as the work would be 

 carried on by insects if birds were not present 

 their efforts cannot be assumed to play an essen- 

 tial part in cross-pollination. On the other hand, 

 ripened seeds like beggar 's-lice and cockles are 

 specially constructed to adhere to feathers and 

 fur, and may be carried a long distance before 

 their hosts can free themselves. 



Once more, considerable dispersal of vege- 

 tation is due to birds of prey. The osprey when 

 it plunges after carp or perch often clutches a 

 talonful of water-weeds as well as its intended 

 quarry. These are sometimes transported to a 

 tree that overhangs another body of water. 

 There, while the osprey consumes its catch, the 

 weeds drop down into the new water. At the 

 same time the contents of the fish's stomach drip 

 into the lake, carrying great numbers of minute 



