96 FIELD AND LABORATORY STUDIES OF CROPS 



carried long distances by the wind. The manner in which 

 the burrs of burdock, cockle burrs, Spanish needles and 

 beggar lice stick to the hair of animals and to the clothing 

 of persons, is familiar to all. Many plants, such as the 

 wild raspberry and pokeweed, have fleshy fruits that are 

 eaten by birds and the hard seeds pass through undigested. 

 Many of these seeds germinate and grow wherever dropped. 



