576 THE AMERICAN NATURALIST.  [VOL. XXXIII. 
represented by Fig. 75, a reduction of this area has taken place ; 
while in the Blattide (Fig. 74) the three anal trachez are pre- 
Fic. 76. — Wings of a nymph of Conocephalus. 
served and the second and third have been specialized by addi- 
tion, these trachez consisting of several parallel branches. 
The cubital trachea is reduced to a nearly simple condition 
Fic. 77. — Hind wing of a nymph of Scudderia. Dotted lines indicate adult venation in part. 
in the Acridid (Fig. 75); but in the other forms examined acces- 
sory tracheze are developed on the caudal side of trachea Cu. 
In the males of the Locustide (Fig. 76) and of the Gryllidz 
(Fig. 79) the formation of a musical organ has been attained 
