NUMBERS AND LOCAL DISTRIBUTION. G9 
the pupa, with all its members straight and still held by their tips within the exuvium 
(frontispiece, fig. 4). The imago then gradually bends backward and the members 
are loosened and separated. With the tip of the abdomen held within the exuvium, 
the rest of the body hangs extended at right angles from it, and remains in this position 
from ten to thirty seconds or more, the wing pads separating, and the front pair stretch- 
ing at right angles from the body and obliquely crossing the hind pair (frontispiece, 
figs. 5and 6). They then gradually swell, and during all this time the legs are becom- 
ing firmer and assuming the ultimate positions. Suddenly the imago bends upward 
with a good deal of effort, and, clinging with its legs to the first object reached, whether 
leaf, twig, or its own shell, withdraws entirely from the exuvium, and hangs for the 
first time with its head up (frontispiece, figs: 7 and 8). Now the wings perceptibly 
swell (frontispiece, fig. 8) and expand until they are fully stretched and hang flatly 
over the back, perfectly transparent, with beautiful white veining (frontispiece, fig. 9). 
As they dry they assume the roofed position (frontispiece, fig. 10), and during the night 
the natural colors of the species are gradually assumed (frontispiece, fig. 11). 
The time required in the transformation varies, and, though for the splitting of the 
skin and the full stretching of the wings in the flat position the time is usually about 
twenty minutes, it may be, under precisely similar conditions, five or six times as long. 
But there are few more beautiful sights than to see this fresh forming Cicada in all the 
different positions, clinging and clustering in great numbers to the outside lower leaves 
and branches of a large tree. In the moonlight such a tree looks for all the world as 
though it were full of beautiful white blossoms in various stages of expansion. 
A more realistic idea of the important stages in this transformation — 
is furnished perhaps by a series of photographs kindly given to the 
writer by Mr. Robert A. Kemp, of Frederick, Md. (see PL AVS Dyess 
more natural position is given if figs. 1 and 2 are turned so as to make 
the twigs perpendicular rather than oblique. 
THE ADULT INSECT AND ITS HABITS. 
NUMBERS AND LOCAL DISTRIBUTION. 
In the case of a well-established brood under favorable conditions, 
the enormous numbers of these insects in the soil is most vividly 
conveyed by the accompanying photograph (fig. 40) taken by Mr. 
Kemp in 1902 (Brood X), near Frederick, Md. Within the foot- 
square area in the center of the photograph are no less than 84 
openings, which would indicate for the ground surrounding a fairly 
good-sized tree the emergence of from 30,000 to 40,000 Cicada pupe. 
Mr. McCook took the trouble to count or estimate the burrows 
under various trees. Under one tree he counted 9,000 burrows, and 
under another, a small birch, the number of exit holes was esti- 
mated at 22,500; and since many of the burrows interlaced under 
ground and several insects emerged from the same opening, even 
these figures do not indicate the actual number. In another case 
668 openings were counted in a space 10 by 4 feet, and 17 distinct 
openings in a space 6 inches square. 
Mr. Davis, referring to Brood IIT on Staten Island in 1894, says: 
About some of the trees the pupa shells became so numerous that they completely 
hid the ground itself. At dusk the sound of the many insects climbing up the tree 
