3 



west. When these weeds ripen, they break off close to the ground ; 

 and being light, they are easily carried by the wind, especially on an 

 open prairie, and the seeds drop out as the weed rolls from place to 

 place. 



An examination of snow drifts in Dakota, a few j^ears ago, showed 

 the presence of many weed seeds. Thirty-two seeds of nine species 

 were found in two square feet of a drift. In the same place it was 

 observed that a twenty-five mile wind carried wheat seed a distance of 

 thirty rods in a minute. 



Seeds which become sticky when wet often adhere to leaves, and 

 go wherever the leaves are carried by the wind. This is true of the 

 Plantain. 



2. By water. Some seeds, especially those of aquatic plants, are 

 distributed by water. Darwin maintained that many seeds, dropping 

 into the sea or being washed in from the shore, might be carried nearly 

 thousand miles by the movements of the water without injuring 

 their vitality. Seeds which fioat on the surface of water are carried 

 to and fro by the wind till they find a lodgment and begin to grow ; ' 

 and many, of various kinds, are carried from high to low ground and 

 distributed far and near by the rills and streams which flow from 

 mountain, hill, and upland after heavy rains and spring thaws. The 

 common Speedwell and Ragweed are often distributed in this way. 



8. By birds and ot'-er animals. Seeds are distributed by animals 

 in a variety of ways. " It is estimated that about ten per cent, of all 

 flowering plants possess seeds which are dispersed by means of barbed 

 or cleaved processes." By these barbs or processes the seeds cling to the 

 feathers of birds and the hairy coats of animals, and in this way are 

 carried from place to place. To this class belong the Bur, Burdock, 

 Hound's Tongue, Bedstraw, Cockle, and such like, xlnd the seeds of 

 some plants, such as Mistletoe and the Meadow Saflron, exude sticky 

 substances which cause them to adhere to birds and other animals. 



In the hardened earth taken from the feet of birds Darwin found 

 a large number of seeds, many of which germinated ; and it is un- 

 doubtedly true that seeds are often conveyed from one place to 

 another in the dirt that clings to the feet of animals. 



Seeds often pass through the stomachs of animals without being 

 digested ; and during their passage they are conveyed hither and 

 thither by the animal and finally deposited, to grow and reproduce 

 their kind, whether of weeds or useful plants. Every farmer knows , 

 the truth of this statement as regards cattle, horses and swine ; and 

 it may be mentioned that Darwin picked from the excrement of small 

 birds twelve kinds of seeds which were perfect in form and germin- 

 fcited in nearly every instance. 



Ants, locusts, and other insects also, do something in the way of 

 distributing the seeds of certain plants, including noxious weeds. 



