GLOSSARY 281 



two pairs of jaws acting horizontally between them, the mandibles 

 and maxilloe. The maxilla; and labium are each furnished with a 

 pair of feelers, known respectively as the maxillary and labial 

 palpi. No organs in the body vary more than the mouth-parts, 

 but they have been divided into two great groups, the biting and 

 the sucking. Among these many minor differences occur. Thus 

 of the biting insects, some require jaws suited for seizing and 

 tearing prey ; others are vegetable feeders, and. their jaws are 

 adapted for chewing. Of the sucking insects, some have merely 

 a sucking tube, to sip up the nectar from flowers ; others art in- 

 strument to pierce the coverings of animals, before they can obtain 

 the living fluid. 



Natural Selection, or the Survival of the Fittest. The natural preser- 

 vation of such differences and variations as arise, and are beneficial, 

 to the individual, and the destruction of those which are injurious, 

 under its conditions of life. By this principle, the individuals 

 which in any way, even the slightest, have the advantage over 

 others which are strongest, swiftest, most protected, &c. have 

 the best chance of surviving, and of propagating their kind. 



Neuration. Or venation, the arrangement of the so-called " veins "or 

 " nerves " in the wings of insects. 



Neuters. See Workers. 



Ntitrition. That process, peculiar to living bodies, by which food is 

 finally converted into the substance of tissues and organs, thus 

 repairing waste and admitting of growth. 



Nyinpli. Old name for pupa. Now generally used to designate the 

 latter portion of the life of an insect with an incomplete metamor- 

 phosis, previous to its change to the winged and mature state ; an 

 active pupa. 



Oblique. Not perpendicular, not parallel, deviating from the straight 

 line. 



Ocelli. See eyes! 



(Esophagus. See gullet. 



Order. An assemblage of families having structural features in 

 common. 



Organism. An organised being, be it plant or animal. 



Orthoptera. Straight-winged. Grasshoppers, locusts, crickets, 

 walking-stick insects, cockroaches, &c. The larvae when they 

 quit the egg differ principally from the mature insects merely in 

 the absence of wings. They are active throughout life. 



Oval Egg-shaped, oblong. 



Ovipositor. Generally the most conspicuous appendage of the abdomen 

 is the ovipositor of the female, an instrument whereby she lays her 

 eggs. Its form is various, and sometimes it is of great length. In 

 the Hymenoptera (which see) it is frequently modified into a 

 sting. 



Palpi. Jointed appendages, or feelers, placed on the lower jaws 

 (maxilla) and lower lip (labium) of the mouth in insects. 



Papilionaceous. The Papilionacece is a sub-order of plants belonging 

 to the large and important natural order Leguminosre. From a 



