67
INTRODUCTION TO ENTOMOLOGY.
"On reconnaîtra partout l'empreinte de cette Intelligence adorable, qui crayonna, de la même main, l'Homme et la Mouche."—Bonnet, Contemp. de la Nature.
Insects form a portion of that extensive department of animated nature known by the name of Articulated animals. They are so called on account of being composed of joints or segments, a structure which renders their bodies pliant, and thus compensates for one of the inconveniences that would otherwise arise from the want of a vertebral column. Some ancient authors designated them by the term annulata—quasi in annulos secta—and they are frequently described in modern works as annulose animals. They are now referred to five great classes: 1. Annelides, such as leeches and earthworms; 2. Crustacea, such as lobsters and crabs; 3. Arachnides, such as spiders and scorpions; 4. Myriapodes, consisting of juli and
scolopendræ; 5. Insecta, containing beetles, butterflies, &c.
The term insect has likewise been suggested by the structural peculiarity just alluded to, the transverse divisions causing the body to appear intersected or cut into; and the Latin word insectum, from
