262 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
easily effected, often aided by the wind, ease of escape from many 
enemies, etc., and the superiority of this mode in open lands — are 
evident to all. On the other hand, long wings and locomotion by 
flight are disadvantageous amid dense underbrush, where a leap- 
ing mode of progression has decided advantages. Organs unused 
or disadvantageous tend to dwindle and disappear; hence the loss 
of wings. In short, Sightlessness in locusts is a more complete 
adaptation to a leaping mode of progression brought about by 
life in situations where flight is difiicult or impracticable and con- 
sequently disadvantageous. 
"Among other Orthoptera flightless species are numerous both 
in saltatorial and non-saltatorial families. On examination we 
find that genera and species inhabiting trees and shrubs (Scud- 
deria, Microcentrum, Pterophylla, Oecanthus, etc.) and open grassy 
lands (Neoconocephalus) , are prevailingly long- winged, while 
those inhabiting undergrowth (Conocephalus in part, Odontoxi- 
phidium), crevices and caves (Ceuthophili, Decticinae, many 
Blattidae and Gryllidae), or burrows, either of other species or of 
their own make {Cryptocercus, Myrmecophila, Gryllotalpa) are 
very likely to be flightless, an evident adaptation in structure to 
habits directly parallel with that of flightless locusts (compare 
also with ants and termites). 
"On close analysis it is found that Orthoptera frequenting 
habitats involving passage over open spaces of considerable 
extent, such as fields, between trees in forests, and bushes or 
thickets in deserts, are usually long-winged, flying species; and 
others dwelling in an environment of more or less dense, intricate, 
interlacing vegetal growth, be it sub-alpine or tropical, in forest 
or swamp — or in burrows, crevices, etc. — in short, in stations 
where wings are not needed or are at a disadvantage, are very 
generally flightless. 
"The fact that the heavier-bodied female is more frequently 
partially or completely wingless than the male and that the teg- 
mina in the male when used as musical instruments are retained 
in a less degenerate condition (even when entirely useless in 
flight), confirms this view." 
Whatever the cause of this condition, the subject is an inter- 
esting one for experimentation. It may be that the question of 
nutrition is concerned; it is thought to be involved in some 
