66 BIRD-SONGS ABOUT WORCESTER. 



middle of the sand-bank, which it reaches 

 by long subterranean passages which it has 

 excavated for itself. 



The purple-martin (^progne pui'purea)^ 

 the largest and handsomest of the swal- 

 lows, for some inexplicable reason seems 

 to be rather uncommon about Worcester. 

 Whether this is any wise due to the ad- 

 vent of the English sparrow, with which 

 perhaps this bird would be most apt to 

 clash by reason of its similar breeding 

 habits, I am unable to say. 



