MORSE: ORTHOPTERA OF NEW ENCLAND. 233 
the j'oung are forced by luinjier to travel outward in search of 
fresh supphes. As numerous and irresistible as a conquering 
army they march onward, devouring everything edible. Even 
growing shoots and the tender bark of trees and shrubs are eaten, 
and the weather-beaten fibers on the surface of boards, fences, 
and buildings are scraped off by their horny jaws, exposing the 
new, solid wood. Under such circumstances a migratory instinct 
develops in some species, even in the wingless young, and they 
press onward blindly, plunging recklessly into streams, where 
they form masses of struggling insects clambering over and over 
each other as they are swept downward by the current to be 
drowned, eaten by fishes, or perchance to be cast ashore on either 
bank and continue their depredations. On reaching maturity, 
they gather in swarms which darken the air and migrate for 
hundreds of miles, carrying destruction to the districts they 
invade and becoming one of the scourges of the earth. Singu- 
larly enough, the young which hatch from the eggs laid in the 
ravaged territory, which is often unsuited for permanent occu- 
pancy by the species by reason of climatic conditions, are said to 
show a tendency to make a return migration in the direction of 
the land of their progenitors. 
A vivid picture of a serious outbreak here in New England in 
the early part of the last century is on record and is quoted on 
pages 265. 
Courtship. 
Arrived at maturity, activities connected simply with the wel- 
fare of the individual become subordinated to those concerned 
with the perpetuation of the race. Flight is now possible for 
most species, at least for the males, and they seek the presence 
of the other sex, often traveling far in the search. Noctur- 
nal species frequently respond to the attraction of artificial 
lights; winged Roaches, Crickets, and Pygmy Locusts occasion- 
ally come in swarms to street lamps and brilliantly lighted win- 
dows, in some cases undoubtedly flying for miles. At this time 
also special evolutions during flight are characteristic of many 
Band-winged Locusts (Oedipodinae) ; the so-called courtship 
dance of the Carolina Locust is perhaps best known. This I 
have often seen and I can fully subscribe to the statements in 
