TRANSFORMATION OF INSECTS. 



101 



abdomen are situated flat movable appendages like pro -legs, and at the extre- 

 mity is a forked apparatus, by which the body can raise itself and move by 

 leaps. Example — the sugar-louse (Lepi'sma saccharinum. ) 



(11.) Parasz^a (Parasites). Six feet; no other organs of sight except 

 simple (instead of composite) eyes ; the mouth is mostly internal, and con- 

 sists of a snout, which contains a retractile sucker, or it forms a cleft with 

 two lips, two mandibles, and hooks. Examples — the different species of lice. 



(12.) Suctdria (Suckers). Six feet, of which the posterior are the long- 

 est, and adapted for jumping. These undergo a transformation, and acquire 

 organs of motion which they had not at first. The mouth consists of a 

 sucker, which is enclosed in a cylindrical sheath, and is formed of two articu- 

 lated pieces. Example — the flea. 



309. Crabs and spiders, which Linnaeus included among insects without 

 wings, are now formed into two distinct classes — Crustacea and Arachnida. 



310. The arrangement here given is that of KoUar ; but other authors 

 diff^er in their views of the subject. By some the earwig is formed into an 

 order distinct from the Orthoptera. The Thrips is separated as an order 

 from the Hemiptera, the caddice-flies (Phryganea) from the Neuroptera and 

 the horse-flies (Hippobosca) from the Diptera. In a popular point of view 

 the arrangement of Kollar may be considered as sufficiently detailed. 



Subsect. 2. Transformation of Insects. 



The greater number of insects properly so called, with the exception 

 of some without wings, change their form several times during their life in 

 so striking a manner, that a person unacquainted with entomology would be 

 inclined to consider one and the same insect, in diff'erent periods of its exist- 

 ence, as entirely different animals. 



811. Insects, in general, are produced from eggs; a few species alone, in 

 which the eggs are developed in the body of the mother, ai-e viviparous ; for 

 example, the aphis. Shortly after pairing, the female lays her eggs, which 

 are often stuck on, and covered with, a sort of glue, to preserve them from 

 the weather, instinctively in the place best adapted to their development, 

 and which off"ers the proper food to the forthcoming brood. The white- 

 thorn butterfly and the golden-tail moth lay their eggs on the leaves of fruit- 

 trees or other leafy trees, and the latter covers them over with a gold- 

 coloured covering of sflk. The common lackey-moth (^ombyx neustria) 

 fastens them in the form of contmuous rings round the stems of the fruit-trees; 

 and the gipsy-moth (jBombyx dispar) fastens them in a broad patch on the 

 stems of trees or on paling, and covers them with a thick coating of hair. 

 The winter- moth (Gedmetra brumata) lays them singly on the buds of the 

 leaves and flowers ; the printer-beetle (Bostrichus typographus) introduces 

 them between the bark and the albumen, &c. 



312. MoS't insects are developed from the eggs in the shape of worms, 

 which are called larvce. The larvae of butterflies, which are always provided 

 with feet, are called caterpillars ; those of beetles and other insects, grubs ; 

 and, when they have no feet, maggots. In this state, as their bodies increase, 

 the insects often cast their skin, and not unfrequently change their colour. 

 Many winged insects (e. g. cimices, cicadae, grasshoppers, and dragon-flies), 

 in their larva state, very much resemble the perfect insect ; they only want 

 the wings, which are not developed tUl after the last change of the skin. 

 The larva state is the period of feeding, and at this period insects are usually 



