CEREAL PESTS WEEDS 



443 



are also common means of dispersing weed seeds. They 

 are also transferred from farm to farm by the thrashing 



a V f JL b 





Sisymbriom incisum Sisynbrium altissimom Viola 



FIG. 142. Seeds of weeds. Enlarged. 



machine. Seeds of a number of weeds are shown in Figs 

 141 and 142. 



