364 



PHYSICAL GEOGRAPHY. 



3. Nemobius vittatus Harr. is found all over the state, even in the White 

 Mountain region, and extends west as far as Nebraska, and south at least 

 to Maryland. It appears a little earlier than the species of Gryllus, but 

 in the White Mountains not until August. Its chirp is very similar to 

 that of Gryllus, and can best be expressed by ru or rruu y pronounced as 



Fig. 48. 



ru ru ru ru 



ru ru ru ru 



Note of Nemobius vittatus. 



though it were a French word. The note is trilled forcibly, and lasts a 

 variable length of time, sometimes for several seconds; at others it is 

 reduced to a short, sharp click.* 



I once observed one of these insects singing to its mate. At first the 

 song was mild, and frequently broken; afterward it grew impetuous, 

 forcible, and more prolonged ; then it decreased in volume and extent till 

 it became quite soft and feeble. At this time the male began to approach 

 the female, uttering a series of twittering chirps ; the female ran away, 

 and the male, after a short chase, returned to his old haunt, singing 

 with the same vigor as before, but with more frequent pauses ; at last, 

 finding all persuasion unavailing, he brought his serenade to a close. 

 The pauses of his song were almost instantly followed by a peculiar jerk 

 of the body ; it consisted of an impulsive movement backward, and then 

 as suddenly forward, and was accompanied by a corresponding movement 

 of the antennae together, and then apart. The female was near enough 

 to be touched by the antennae of the male during the first movement, and 

 usually started in a nearly similar way as soon as touched. 



The elytra of the male are held at an angle of about twenty degrees 

 from the body during stridulation, and, perhaps, at a slightly greater 

 angle from each other. Even when most violent, the sound is produced 



* It is necessary for me to describe the peculiar system of musical notation which I have adopted. Each bar 

 represents a second of time, and is occupied by the equivalent of a semibreve; consequently a quarter note (0\ 

 or a quarter rest (^) represents a quarter of a second ; a sixteenth note /f\ or a sixteenth rest / JJ\ 



' 



of a second, etc. For convenience' sake, I have introduced a new form of rest 

 silence through the remainder of a measure. 



a sixteenth 

 , which indicates 



