THE ENTOMOLOGIST. 249 
appearance of the latter, hence its untimely decay. If we 
now take a longitudinal section of the swollen midrib, we 
find that it contains a long cell, tenanted by one or several 
reddish-yellow, footless, 14-jointed larve of about a line 
in length. Their food consists of the juices exuding from the 
incrassated sides of their dwelling-place; hence, if we open 
the latter whenever we please, we shall almost always find it 
licked scrupulously dry, but strewn with the black excrements 
of its inhabitants. In about three weeks the larve are full- 
fed, when they become obese and sluggish; the irritation 
their licking produced on the sides of their chamber therefore 
ceases, the sap no longer flows steadily inward, but becomes 
accumulated in the more or less pod-shaped, fleshy halves of 
the gall; a consolidation of the two halves respectively 
ensues, and causes a longitudinal fissure between them on the 
upper side of the midrib, through which natural opening the 
larvzee drop to the ground, in which they bury. Here they 
shortly become sculptured pupe, exhibiting all the limbs of 
the future fly, in thin semi-transparent sheaths, which are 
laid flat along the breast. In about three weeks from the 
time of burying, the mature pupz force their way half out of 
the ground, and the perfect midges, by bursting their silver- 
white pupal skins, make their appearance. A few hours’ 
breathing give them the use of their wings and limbs. They 
are two-winged Cecidomyiz, or gall-midges; and the species 
has been described by Winnertz under the name of Ceci- 
domyia botularia. In its living state it is about a line 
in length; it is reddish-yellow, with a white beak ; its thorax 
shows three narrow, short, pale-brown streaks; the poisers 
are pedunculated and whitish; in the segments the abdomen 
is brown, each segment with a fine brownish lateral streak ; 
the hind border of the segments, above and beneath, is 
fringed with long whitish hairs. The six legs are long and 
slender, brownish, and clothed with a white pubescence. 
The wings are comparatively large, transparent, with sparse 
grayish hairs, and suffused with a weak iridescent violet ; 
their viens are brownish. The feelers are brownish, 26- jointed 
in the male, and 14-jointed in the female; the latter is fur- 
nished with a short ovipositor. The ravages of this midge are 
mostly confined to the lower and protected limbs of the ash, 
and if the underside of the branches is examined, a glance 
