THE SCHOOL GARDEtf. 299 



Some special adaptations to note here are the rosette 

 leaves of Daisy and Dandelion for securing light and room 

 for themselves. Sometimes, e.g. amongst corn crops when 

 tall weeds are numerous, the corn is apt to draw to length, 

 and is thus liable later to fall over. The presence of weeds 

 in numbers also tells particularly upon slow growing crops, 

 which naturally suffer most, e.g. clovers. 



Weeds which climb, e.g. Bindweed (Convolvulus arvensis], 

 are apt to drag down the cereals amongst which they grow, 

 and by winding around them impede the leaves from proper 

 functioning. 



In being mixed up with cereal and other crops weeds con- 

 taminate the seeds of these, lowering their market value, or 

 being sown with these perpetuate the mischief. 



Lastly, weeds may serve as centres of dissemination of 

 fungus pests amongst cultivated plants, e.g. Charlock and 

 " Finger and toe," or serve to maintain insect enemies of 

 crops, e.g. Charlock and turnip beetle. 



Some of the special adaptations favouring the commoner 

 weeds should be emphasised. Note from the foregoing list 

 and from others not included in it : 



Plants appearing early in the year and persisting for a 

 long time. 



Plants with special modes of seed distribution, e.g. by 

 wind. 



Plants with rootstocks which bud vegetative propaga- 

 tion. 



Plants which seed over long periods of the year. 



Perennials which store reserves. 



Plants which germinate quickly. 



Any other adaptations for perpetuating the species. 



