Page:The American Cyclopædia (1879) Volume VI.djvu/672

 660 ENTOMOLOGY attention to the maxillary system he has ena- bled his successors to define certain groups with considerable accuracy. His first classifi- cation of 1775 was greatly modified in the course of his life, and the following was pro- posed by him in his Entomologia in 1798 : I. INSECTS WITH BITING MOUTHS. A. Two pairs of mandibles. a. The lower ones having palpi. 1. Free without covering 1. Class elwtherata Hbeetles). 2. Covered 2. 8. Connate with the labium 8. 4. Distended, thin, coriaceous 4. 5. Horny, strongly toothed, labium without palpi 5. 6. All without palpi 6. B. A pair of scissor-like maxillae T. C. More than two pairs of maxillae. 1. Within the labium 8. 2. Outside the lip, closing the mouth 9. 8. Outside the lip, but covered by the palpi. 10. -ulonata (orthoptera). aynistata (neuropterd). piezata (hymenoptera). odonata (Hbellulce). mitosata (scolopendra). unogata (scorpions and spiders). polygonata (isopoda). pleifflagnatha (short-tailed crabs). exochnata (long- tailed crabs). II. INSECTS WITH SUCTORIAL MOUTHS. 1. In the mouth a spiral tongue 11. Class glossata (lepidopt&ra). 2. A horny proboscis, with jointed sheaths 12. " rhyngota (hemiptera). 8. A soft, unjointed proboscis 18. " antliata (diptera). The facility with which genera were deter- mined by this system secured for it many fol- lowers, in spite of its unnaturalness ; and Illiger, by uniting it with that of Linnaeus, considerably improved it. He made order 1 of Linnaeus correspond with class 1 of Fabri- cius; 2 L. with 2 and 12 F. ; 3 L. with 11 F. ; 4 L. (to which were added termes, lepisma, and podura) with 3 and 5 F. ; 5 L. with 4 F. ; 6 L. (with pediculus and acarus) with 13 F.; and 7 L. (without the above named apterous gen- era) with 6, 7, 8, 9, and 10 F. Olivier, in the article Insectes in the Encyclopedic methodique, follows chiefly the Linnaoan classification, modi- fied by Geoffroy and De Geer, making use of the wings and elytra, the parts of the mouth, and the joints of the tarsi in his divisions ; he substituted the term orthoptera for the der- maptera of De Geer ; in his order aptera ai^ still included spiders, crabs, and myriapods. In Olivier's great work on coleoptera, in six large quarto volumes with nearly 400 plates, published between 1789 and 1808, may be found the largest collection of representations of this order yet known. Latreille's first work, published in 1796, presents the insects of Lin- naeus in 14 classes, adding orthoptera, to the Linnsean system, and separating the aptera'mto suctoria, thysanoura, parasita, acephala, ento- mostraca, Crustacea, and myriapoda; this sys- tem, though in many respects unnatural, claims the positive merit of introducing some natural families. In 1810 he adopted a new classifica- tion, following Ouvier and Lamarck in sepa- rating Crustacea and arachnids from insects proper, and dividing the latter into the 7 orders of his first classification, adding the order suctoria (formed entirely by the genus pulex). In 1817 he added myriapoda, thysa- noura^ and parasita to his 8 orders, and also strepsiptera of Kirby ; in 1825 he raised the myriapoda, after Leach, to a distinct class, and divided the insecta into 11 orders; in 1829 he reduced the myriapoda to an order among in- sects, raising the number again to 12 orders, and in 1832 raised them again to a class inter- mediate between arachnids and insects. One great merit of Latreille is that he gave family names to the groups of genera, which Macleay has reduced to system by giving to them the termination idea, which, if not always classi- cally correct, is of advantage for uniformity and euphony. Lamarck divides insects into 8 orders: 1. Insects with suctorial mouths: 1, aptera {suctoria, Latr.); 2, diptera; 3, hemip- tera ; 4, lepidoptera. II. Insects with man- dibulate mouths : 5, hymenoptera ; 6, neurop- tera ; 7 ', orthoptera ; and. 8, coleoptera. Other aptera he placed among arachnids and crusta- cea, and ranked thysanoura, myriapoda, and parasita among arachnids. Dumeril places insects above mollusca in the animal series, and comprises among them arachnids and myria- pods ; his arrangement differs but little from the Lmnsean ; he endeavored to reunite the greatly divided families, and to reduce the number of genera. The philosophical systems of the modern German school proceed, on the view that organic nature is one great whole, exhibiting progressive grades of development, which are characterized as classes. Oken has made 13 classes of animals, each represented by a successively added organ. Insects form the 9th class, and are called lung animals ; they are divided as follows : I. Germ flies, with per- fect metamorphosis, with tribes : 1, hemiptera ; 2, orthoptera and dermaptera; 3, neuroptera. II. Sexual flies, with perfect metamorphosis and equal wings, with tribes: 4, diptera and suctoria; 5 hymenoptera; 6, lepidoptera. HI. Lung flies, beetles, with perfect metamorphosis, elytra, and wings, with tribes: 7, C. tetrame- ra ; 8, C. heteromera ; and 9, G. pentamera. Among the English writers who have contrib- uted to the advance of entomological classifi- cation may be mentioned Leach, Kirby, and Macleay. Dr. W. E. Leach published several elaborate treatises on insects in the " Linnsean Transactions," and in the British and foreign encyclopaedias ; his system is sketched in vol. iii. of the " Zoological Miscellany." He divides insects into ametabola and metahola, according to the absence or occurrence of metamorphosis, the former including 2 and the latter 14 orders ;