140 



FIEST STUDIES IN PLANT LIFE 



11. How seeds are spread by man. There stand 

 in Eome to-day the ruins of the CoHseum, a great 

 circus of stone. Among these ruins rare plants are 

 found, due, it is supposed, to the seeds brought from 

 the ends of the earth on the sandals of Eoman soldiers. 

 In similar ways the Crusaders brought new plants to 

 England. For many centuries ships have carried 

 fodder for cattle and grain for fowls, and in this 

 way seeds have often been swept from the deck to 



the sea and borne to 

 land. The cockle-burr is 

 said to have sprung up 

 in New Zealand from bal- 

 last landed by a ship 

 from South America. 

 Seeds, again, are often 

 contained in the straw 

 or grass used to pack 

 cases of goods. To this 

 we owe many of our 

 weeds. Then there is 

 the trade in seed from 

 one country to another. 

 When you sow clover- 

 seed bought in Europe 

 you may sow with it 

 weed-seeds that are so like the clover-seed that they 

 are not noticed. We have in Australia the hog-weed, 

 sorrel-weed (fig. 101), sow-thistle, the scarlet pim- 

 pernel, lucerne-dodder, and many other of the weeds 

 and wild flowers of Europe. The cockle-burr is said 

 to have been brought into Australia with cotton seed 

 sown in Queensland. 



Common sorrel-weed. 



