SEED DISTRIBUTION. 



293 



ibeggar-ticks or stick-tights, or sometimes called bur-marigold 

 ((bidens), the tick-treefoil (desmodium), or cockle-bur (xan- 

 thium), and burdock (arctium). 



458. Dissemination by water. — Other plants like some of 

 the sedges, etc., living on the margins of streams and of 

 lakes, have seeds which are provided with floats. The wind 

 or the flowing of the water transports them often to distant 

 points. 



459. Dissemination by animals. — Many plants possess at- 

 tractive devices, and offer a substantial reward, as a price for 



Fig. 247. 

 Seeds of geum showing the hooklets where the end of the style is kneed. 



the distribution of their seeds. Fruits and berries are devoured 

 by birds and other animals; the seeds within, often passing 

 unharmed, maybe carried long distances. Starchy and albumi- 

 nous seeds and grains are also devoured, and while many such 

 seeds are destroyed, others are not injured, and finally are 

 lodged in suitable places for growth, often remote from the 

 original locality. Thus animals willingly or unwillingly become 

 agents in the dissemination of plants over the earth. Man in 



