80 
THE PERIODICAL CICADA. 
(c'pipharv^nx) and the other (hypopharynx) attaching to the upper 
])ase of the lower hp. These tongues are short and of service, prob- 
ably, in facilitating the suction necessary' in raising the fluids of the 
plant to the mouth. They do not extend beyond the mouth canity, 
and never enter the plant tissues. 
The upper lip is comparatively short, and serves its normal ])urpose 
as a covering for the adjacent parts of the mouth. What correspond 
to the short, powerful biting jaws of gnawing insects are in the Cicada 
greatly elongated and tliread-like, and brought together to form a sort 
of piercing and sucking apparatus, which is inclosed in the greatly 
elongated lower lip. The latter is three-jointed and deeply grooved 
Fig. 33.— Head and prothorax of Cicada, lateral view, with parts separated to show structure: I. a, 
ch-peus, 6 and c, labrum, d, epipharj-nx; 1', same from beneath; II, mandible, a, base, 6, sheath for 
seta, c, mandibular seta, c', muscular base of latter; III, maxilla with parts similarly lettered; IV. 
labium, with three joints as follows, o, submentum, 6, mentum, c, ligula; the hj'popharjTix is shown 
at d, from side, d', from above, and d", from beneath; V, prothorax. (Author's illustration. i 
above so as to be almost tubular, and acts as a support and sheath for 
the piercing seta-Uke jaws, and also assists in conveying the liquids 
from the point of contact with the plant to the mouth cavity. The 
long lower lip just described is the piercing beak in popular belief, yet 
in point of fact it never enters the tissues of the plant, the puncture 
being made solely by the fine, stiff, needle-like jaws or setie, which can 
])e ])rojected at will by the insect with great force from the tip of the 
beak. (See figs. 31, 32, 33, and 34,a.) 
The feetling habits of the adult Cicada are discussed on pages 101- 
1 {)'!. The main feeding is, however, during the long adolescent period, 
comprising the larval and pupal existence of the insect under the soil. 
