(o THE PERIODICAL CICADA. 
which are partly broken off, but in such instances the flow of sap has 
not been entirely stopped. 
The after effect of the egg punctures on the twigs is shown in the 
deformity which characterizes their subsequent growth. In the pro- 
cess of healing the punctures usually assume a wart or knot like 
appearance, as represented in the accompanying illustration of an 
apple twig (fig. 31.) The effect of punctures in hard maple twigs after 
the lapse of seventeen years is shown in fig. 32, and on various plants 
in Plate I (see p. 10) these illustrations being kindly loaned me by Mr. 
Hopkins. 1 Though ultimately healing over exteriorly with the growth 
of the surrounding wood, there remains in the center of the twig a dead 
spot, and the white, glistening egg shells of the escaping larvae have 
been found in place six years after they have been inserted in the twig 
by the female Cicada. 
Considerable danger follows the work of the Cicada, in that as long 
as the wounds remain open or as dead spots on the limbs they are not 
only a source of weakness in the case of winds, but they offer attract- 
ive situations for the attacks of various wood-boring insects. If left 
to themselves the limbs might entirely recover, except for the scars, 
but the borers gaining entrance through these spots complete the work 
of destruction which the Cicada began. Furthermore, such open 
wounds or pockets in the twigs of fruit trees Mr. Hopkins has shown 
to be favorite points of attack for the woolly aphis, the presence of 
which not only prevents the wounds from healing but causes additional 
abnormal growth, adding considerably to the injury to the branches, 
aud making them more liable to the attacks of other insects. 
METHOD OF INSERTING THE EGGS. 
The work of the female Cicada in inserting her eggs is an interesting 
subject for study, and so little does she mind the presence of an 
observer that the operation can be closely watched without her exhibit- 
ing any alarm. The position taken is almost invariably with the head 
upward or directed toward the tip of the branch, the work being steadily 
prosecuted in that direction. When her course is interfered with by 
the occurrence of side shoots, instead of moving to one side or the 
other she reverses her position and thus follows her row of punctures 
in a straight line completely to the base of the intervening shoot. The 
branch selected is ordinarily of a size which the female can surround 
and clasp firmly with her legs to give her the strong attachment neces- 
sary to enable her to force her ovipositor into the woody tissues. 
The exact method of making the egg fissure and depositing the eggs 
has hitherto, in the main, been either very briefly referred to, or the 
actions of the insect have been inaccurately interpreted. The descrip- 
tion of this process, hitherto generally accepted and quoted, is that given 
by Dr. Harris, substantially as follows: Raising her body somewhat 
N i Bulletin 50, W. Va. Ag. Ex. Sta., Pis. II and IV. 
