

50 THE EELATION OF SPAEROWS TO AGRICULTURE. 



without removing an 3^ of the ensheathing glumes. Gravel was fur- 

 nished so that the grinding power of the birds' gizzards might be 

 facilitated, and after several hours 6 droppings were collected and 

 examined. No whole seeds were found. There were, however, three 

 nearly entire glumes and a i3ulverized mass of matter which under 

 the microscope was seen to consist of fragments of broken glumes. 

 Several days later about 500 crab-grass seeds were fed to the same 

 sparrows, no gravel being given at the time or during the interval 

 between the two experiments. Twelve droppings were examined and 

 the results were substantially the same as in the first experiment. 

 Three different sparrows were then fed with about 1,000 crab-grass 

 seeds and 20 droppings were collected. The result Avas the same. 

 Nor one of the 1,600 seeds was passed in a condition to germinate. 

 Although these experiments are by no means conclusive, j^et they 

 strongly indicate that the English sparrow, however harmful it may 

 be in other ways, can not be held responsible for the occurrence of 

 crab-grass in lawns. It is possible that the damage is due to the 

 wind. Seeds of crab-grass are light and buoj^ant, and those attached 

 IjjII to fallen spikes would be particularly likely to be carried along by 



the wind on gust}^ days. 



''S 



