112 NATURAL HISTORY. 



These insects live upon trees and shrubs, and obtain their nourishment by piercing the tissues 

 and sucking out the juices of their young tender shoots. In some cases the How of juice continues 

 after the withdrawal of the pumping apparatus of the Cicada, and the fluid hardening on the surface 

 of the twigs becomes the substance known as Manna.* This applies especially to a species that 

 infests ash-trees in most parts of Europe and over a considerable portion of Asia (Cicada orni), which 

 is, in fact, the common Cicada of Southern Europe. 



The female Cicada is furnished with a powerful serrated ovipositor, by means of which she cuts 

 deeply into the dead branches of the trees on which she lives, and deposits her eggs in the grooves 

 thus formed. The larvae, when hatched, are little, plump, stout-limbed insects, and they speedily 

 make their way beneath the surface of the ground, where they live by sucking the juices from 

 the roots of trees and plants. They appear generally to pass at least two years in their preparatory 

 states, and some are said to be much longer in arriving at maturity. One North American species 

 is called the Ssventeen-years' Locust (Cicada septendecini), because it is said to appear only at intervals 

 of seventeen years in any given locality. 



The male Cicadas are endowed with a noise-producing power which renders them most trouble- 

 some in places where they abound. During the heat of the day they sit concealed among the 

 foliage of the trees and shrubs, and sing incessantly. This habit has been referred to by the 

 classic poets in many passages, which indicate that for some reasons the song 

 of the Cicada was regarded by them as by no means unpleasant, and, in fact, 

 even at the present day, in countries where the insects abound, it is a common 

 practice to keep them in cages, probably for the purpose of reminding town- 

 dwellers of the delights of the country. The organs by which this often violent 

 stridulation is produced are situated at the base of the abdomen, in two cavities 

 enclosed by large horny plates, which are represented upon a smaller scale in the 

 females also. The special organs enclosed in these cavities consist of elastic folded 

 membranes attached to a horny ring, snd the noise has generally been described 

 as produced by vibrations of these membranes, caused by the action of muscles 

 originating from the median partition of the second abdominal segment. According 

 to Dr. Landois, however, the " drum," as the above-mentioned special membrane 

 has been called, cannot act in the manner described, but is firmly attached to the 

 wall of the metathorax. He considers the true organs of sound to be the 

 UNDER SURFACE OF stigmata of the metathorax, which are very large and elongated, and furnished 

 MALE CICADA. throughout their length with a pair of thin sound-bands, leaving a very narrow slit 

 between them. The vibration of these bands during the expulsion of air from the 

 trachea produces the sound, which the external organs only increase in power. The females have no 

 voice, as was well known to the ancients in fact, one Greek poet most ungallantly congratulates the 

 male Cicadse on the silence of their partners. 



FAMILY XIV. 



In these insects, as in the two succeeding families, there are never more than two ocelli, 

 but these are rarely wanting, and are placed near the compound eyes. The head is exceedingly 

 variable in its form, but the forehead is always separated both from the crown of the head and from 

 the cheeks by well-marked ridges or keels. The antennae, which consist of three joints, and ai*e 

 usually short and terminated by a bristle, spring from the cheeks beneath the eyes ; the prothorax is 

 a simple ordinary segment ; the middle coxae are elc a gated and widely spread, and the tibiae are 

 generally three-cornered and often spinous. The hin i limbs are usually leaping organs, and their 

 tibiae have a circlet of spines at the apex, often accompanied by one or two of larger size. There is 

 no trace of singing organs such as are possessed by the Cicadfe. In many of the Fulgoridae the front 

 of the head is produced into processes, sometimes of the most fantastic form ; and most of them 

 produce from the skin a sort of waxy secretion, which usually forms white powdery-looking patches on 

 the abdomen, but is frequently much more abundant, and constitutes stout white threads, which may 

 entirely cover and conceal the abdomen, and extend for some distance beyond its apex. This 



* Most of the manna of commerce, however, is obtained artificially by incisions made in the bark of the ash-trees. 



