RELATION TO AGRICULTURE 35 



Crab-grass 2,000 



Curled dock 4,175 



Dodder 1,560 



Evening primrose 10,000 



Lamb 9 s quarter 15,000 



Milkweed 770 



Peppergrass 2,400 



Pigweed . . 12,000 



Plantain 12,500 



Rabbit-foot clover 30,000 



Round-headed bush clover 1,800 



Smartweed 2,250 



White vervain 18,750 



Water smartweed 2,000 



In addition to this enormous capacity for seeds, 

 the bob-white accounts for 145 species of insects. 

 It is calculated that quail consume 1341 tons of 

 weed seeds in North Carolina and Virginia be- 

 tween September 1 and April 30. The mourning 

 dove is accredited with 7000 seeds daily. The 

 work of finches is highly beneficial, that of the 

 winter birds being particularly so. 



On the Maryland farm above mentioned Dr. 

 Judd found that slightly more than a quarter of 

 the birds killed ate weed seeds. Seeds formed 

 about one fifth of all the food consumed by birds 

 on the farm, and, in the case of some individuals, 

 formed from 50 to 70 per cent, of their food. 

 The number destroyed to the acre in twenty-four 



