20 COMMON WEEDS 



animals, and are rubbed off at a distance from their 

 source (e.g. Burdock, Cleavers). Others again are 

 devoured by animals and birds, and, being undigested, 

 are passed through the alimentary system unharmed, 

 and deposited in the faeces perhaps miles away from 

 their original home. Birds frequently carry succulent 

 fruits and seeds to favourite positions in order to eat 

 them at leisure, and in various ways leave or lose them. 

 Squirrels, mice, and other seed- or fruit-eating animals 

 also aid in the distribution of plants in a similar 

 manner. 



(c) Weeds are Spread by means of Seeds mixed in 

 Samples of Agricultural Seeds. Either through careless- 

 ness or inadvertency weed seeds are introduced into 

 fields at the time these are seeded for a crop. Most 

 or all of our agricultural seeds are frequently impure, 

 containing as we shall see later large numbers of 

 weed seeds ; these are thus sown with the good seed, 

 after which, in many cases, " the tares and the wheat " 

 must grow together until the harvest. Although such 

 distribution of weeds is doubtless generally due to care- 

 lessness, it is also perhaps frequently to be attributed 

 despite the extension of present-day knowledge to 

 ignorance on the part of those chiefly concerned. 

 Perhaps most seedsmen worthy of the name supply 

 good clean seed, but there come into the market many 

 samples which have been only very imperfectly cleaned 

 if at all, and these find their way through irresponsible 

 dealers to many of the farms of this country. Any 

 individual or firm found to supply samples of seed 

 containing more than the minimum of impurity should 

 be studiously ignored. 



Many weeds are introduced from other countries in 

 the large quantities of clover, grass, and other seeds 

 which are imported. Dodder especially is introduced 



