102 NATURAL HISTORY. 



the basal cleft already mentioned. This cleft is closed by the more or less elongated labrum, which 

 fits into it, and thus completes the tube. Within this tube we find four bristles representing the 

 mandibles and maxillae, which can be pushed forward and retracted by the action of muscles attached 

 to their slightly enlarged bases, and thus serve, like the similar organs of the Diptera, to pierce 

 the tissues of animals and plants, and enable the insects to suck up their juices. There are no 

 maxillary palpi. 



The general form of the body varies exceedingly, and so does the relation of the head to the 

 thorax, but, as a rule, the three segments of the thorax are distinct and separate, and bear two 

 pairs of wings, the texture of which differs much in the different subordinate groups. Usually the 



prothorax is greatly developed 011 the upper surface, and behind it we 

 find a regular scutellum. In both theso respects, as also in the frequent 

 conversion of the fore wings into horny wing-cases, the Rhynchota 

 resemble the Beetles. The tarsi never consist of more than three joints. 

 The abdomen is formed of from six to nine segments, which, in those 

 species which have horny fore wings, are horny only on the lower surface, 

 and on this the stigmata are situated. 



Unlike the Diptera and Lepidoptera, the Rhynchota have no crop 

 or sucking stomach appended to the oesophagus, which leads directly 

 into a glandular stomach, followed by a long, convoluted intestine, often 

 dilated in its course into a stomach-like sac. The last portion of the 

 intestine is also frequently glandular, and receives the Malpighian vessels, 

 of which four are generally present. The salivary glands are usually 

 much developed and often of complicated structure, or furnished with 

 complex salivary receptacles. Besides these glands, we find in the Bugs 

 a glandular organ situated in the metathorax, which secretes a strongly 



HEAD OF CICADA PLEBEJA. and g enerall y disagreeably scented fluid, discharged through a pair of 

 i. Labrum; 1,2. 3. Joints of Rostrum, special orifices close to the origin of the posterior pair of legs. The 



nervous system is very much condensed. Behind the head-ganglia the 



ventral chain generally shows only two thoracic ganglia, of which the second is larger than its 

 fellow, and evidently composed of two ganglia united into a single mass. The abdominal part of the 

 chain is represented only by a pair of nerve-cords, from which nerves are given off to the various 

 organs. In nearly all the Rhynchota \ve find a pair of compound eyes, generally of small or moderate 

 size, and either two or three ocelli. The other sense-organs, the antennae, vary greatly in structure, 

 being sometimes quite short, composed of two or three joints and terminated by a bristle, sometimes 

 long, and then consisting either of four or five joints of considerable length, or of a greater number 

 up to about twenty. 



The metamorphosis throughout the order is imperfect ; indeed, in the PEDICULINA, there is 

 no metamorphosis at all. The larvae present a greater or less resemblance in general form to 

 the perfect insect, and as they grow and change their skin the rudiments of the wings make their 

 appearance and gradually increase in size, lying in cases placed on each side behind the prothorax. 

 There is consequently no true pupa stage, the imago being gradually produced under the successive 

 larva skins until the final moult; but the last stage before this takes place is usually denominated the 

 pupa. The insect is active and has similar habits throughout its life, the only exception to this 

 rule being presented by the males of the Cochineal insects, which become resting pupse underneath 

 the last larva skin, and are sometimes enclosed in a small cocoon. 



The food of most of the insects of this order consists of the juices of plants, which they suck up 

 after piercing the tissues, as above mentioned, with the bristles which represent the mandibles and 

 maxillae. Some of these vegetable feeders have been observed occasionally to attack other insects and 

 feed upon their juices, and the species of certain families are predaceous in their habits, and live 

 entirely upon animal food. The Pediculi are parasitic upon Mammalia, whose blood they suck. 



The species are found in all parts of the world, but the tropical regions are most favourable to 

 their development, and it is here that we meet with the greatest number of species, and that they 

 attain the largest size, the most curious forms, and the finest colours. Some of them are among the 



