162 STUDIES IN THE FIELD AND FOREST. 



sionally, during an interval of silence, the night-jar, as 

 he flies invisibly over our head,* twangs his wings on a 

 sudden descent through the air in pursuit of his aerial 

 prey, making a sound that to the superstitious, who are 

 unacquainted with the habits of the bird, is fearful and 

 mysterious. The first time I heard this sound, which 

 resembles the snapping of a viol string, was in my 

 school-days, when walking homeward with three of my 

 school-fellows, at midnight, on a solitary turn pike-road. 

 Not knowing the cause of it, we were affected with a 

 peculiar sensation of awe, which was not relieved until 

 daylight revealed to us the birds still circling above our 

 heads. 



Often while thus affected with a sensation of mys- 

 tery bordering on that of sublimity, and in the midst of 

 a stillness that is somewhat awful, all serious emotions 

 will be put to flight, by a sudden chorus of bull-frogs 

 from a neighboring pool. These sounds, in themselves 

 inharmonious, are so suggestive of the sweetness and 

 the quiet of a summer evening in the woods, that they 

 seldom fail to impress the mind with agreeable emo- 

 tions. In the course of our midnight saunterings, 

 when we are near any collection of water, the shriek of 

 the common green frog is heard incessantly, at short in- 

 tervals, and the trilling voice of the toad, so continual 

 by day, occasionally breaks the silence of night. The 

 common tree-frog, the prophet of summer showers, 

 which is seldom heard except in damp days, keeps up 

 a constant garrulity, ending only with sunrise, during 

 all still nights in the month of June. 



There is no perfect stillness on a summer night. 



* Tliis sound is said to be produced by the open mouth of the bird, 

 as he darts swiftly through the air in pursuit of an insect. 



