REVIEW OX SEED DISPERSAL 



1G3 



for food, but if they are not eaten they may grow. The seeds of 

 many plants are blown on the snow. The old stalks of weeds, stand- 

 ing through the winter, may serve to dis- 

 seminate the plant. Seeds are carried by 

 water down the streams and along Bhores. 

 About woolen mills strange plants oft en 

 spring up from seed brought in the fleeces. 

 Sometimes the entire plant is rolled for 

 miles before the winds. Such plants are 

 "tumble-weeds." Examples are Russian 

 thistle (Fig. 99), hair-grass or tumble-grass 

 (Panicum capillare), cyclone 

 plant (Cyeloloma platyphyl- 

 luin), and white amaranth 

 (Amaranthus albus). About 

 seaports strange plants are 

 often found, haying been 

 introduced in the e a rt h 

 which is used in ships for 

 ballast. These plants are usually known as "ballast plants." Most 

 of them do not persist long. 



It 



, i ' 



\ zinc-lined boi may be fitted t" the Khool room windon and need 

 H-, .-i receptacle for plant ' under one corner will drain off the 



accumulated water. Geranlnm. eolena, grerillea, eome I and 



other pi. ints ni.i> be grown in the condition! which are prenl in moil 

 school-rooms. If the plant* become lick, ink.- them to it"' it"' 



