THE HETEROPTERA. 549 



small projections. Two hair-like appendages are attached to the tail ; and in some 

 species, such as that which is selected for illustration, the creature is further decorated 

 with a tuft of downy and snowy white hairs. Before the male has changed into the 

 pupal form, both he and his future mate have affixed themselves to the tree by means 

 of their beaks, and have remained motionless for several months. 



The change undergone by the female is, perhaps, the most singular in the annals of 

 entomology. In her preliminary stages, she was a brisk, active, six-legged little creature, 

 with antennae at her head and two long setas at her tail. But when she approaches the 

 state which we must call " perfect," though in truth the creature seems to lose perfec- 

 tion as it advances in development, she fastens herself tightly to a branch, loses all 

 vestige of limbs, head, or the least sign of her insect condition, the edges of her body 

 enlarge, and are pressed closely to the bark, and her back swells enormously, until she 

 looks like one of the galls that are often found on bark, and bears no small resemblance 

 to a limpet with rounded back. In some species, the body is enveloped in a white 

 cottony secretion, and in others a kind of wax is poured forth. The only advantage 

 which she seems to possess over the male is, that she has a three-jointed beak, which 

 she can drive into the tree, and by means of which she can obtain the nourishment 

 necessary for this enormous growth. The male, on the other hand, has no mouth at 

 all, nor does he need one. 



Within the shell-like body the young Cocci are hatched, amid an abundant supply 

 of white substance, something like flour. The mother by this time has died, but her 

 shelly skin still remains, and forms a house wherein her children live until they are 

 strong enough to enter the world. They are usually hatched towards the end of June, 

 and the young escape at the end of July. 



The COCHINEAL INSECT (Coccus Cacti} belongs to the same genus. This species is a 

 native of Mexico, and lives upon a kind of cactus, called, from its insect guest, the 

 Cactus cochnielifer. The wonderful amount of rich coloring matter which these insects 

 contain is well known. The beautiful colors carmine and lake are obtained from this 

 insect, and the best scarlets are likewise produced from the Cochineal, the difference 

 of hue being due to a mixture of chloride of tin. The trade in the Cochineal is very 

 great ; and as the substance is very costly, and permits a parcel of great value to be 

 compressed into a small bulk, it is often used in lieu of cash in mercantile transactions, 

 and a package will go traveling backwards and forwards for a long time before it 

 reaches its final destination. 



Several other species, such as the POLISH SCARLET GRAIN (Coccus Polonicus), and the 

 KERMES (Coccus Ilicis), are also valuable to colorists, and impart a very fine scarlet to 

 substances treated with them, although the hues are not equal to those obtained from 

 the cochineal. The latter of these insects was known both to the Greeks and Romans, 

 and was used by them for the purpose of obtaining the purple dyes which were so 

 much worn by the higher classes. 



The LAC INSECT (Coccus Laced) is another member of this most useful genus. This 

 species resides in India and the hotter parts of Asia. It is found attached to the twigs 

 of trees, and is then called stick-lac, the shell-lac being the waxen secretion purified 

 and shaped into thin shell-like plate. 



HETEROPTERA. 



THE insects belonging to the large and important order which is placed next to the 

 Homoloptera, are readily known by several conspicuous characteristics. The wings 

 are four in number, and the front pair are very peculiar in their structure, the basal 

 portion being horny, like the elytra of beetles, and the remaining portion membranous 



