GLOSSARY 285 



Type. The perfect representation of anything. Typical, applied to an 

 individual which possesses in a marked degree the characteristics of 

 the species, or to a species similarly exhibiting the essential features 

 of the order. 



Unctuous. Fat, clammy. 



Valve. Folds of membrane which guard certain orifices and channels, 

 allowing any fluid to pass in one direction, but offering a barrier 

 to its backward movement. 



Venation, or Neuration in Insects. The arrangement of the so-called 

 "veins " or " nerves " of the wings. A wing is first developed as 

 a tiny sac-like projection from the side of the body. As formation 

 goes on, the two walls of this sac become united throughout their 

 greater part, and various thickened lines are usually apparent, 

 which constitute the framework of the wings, and are termed the 

 veins or nerves. Within the latter a canal or tube often exists 

 for the circulatory fluids, and they are likewise traversed by the 

 air-tubes, or tracheae. Venation, in botany, the arrangement of 

 the ribs and veins, or framework, in the blades of leaves. 



Ventral. Pertaining to the abdomen or anterior surface of the body ; 

 the opposite of dorsal. 



Vermiform. Worm-like. 



Vertebrate Animals or Vertebrata. The highest division of the animal 

 kingdom, characterised by the possession in most cases of a back- 

 bone or vertebral column composed of numerous joints or vertebra, 

 which constitutes the centre of the hard internal bony framework 

 or skeleton of the body, and protects the central parts of the 

 nervous system. 



Vilmrnum. (L. the way-faring tree). A genus of elegant flowering 

 shrubs, belonging to the natural order Caprifoliaceae the Honey- 

 suckle family. V. opulus is the common Guelclres Rose or Snow- 

 ball tree, the flowers of which appear in June. So named from a 

 district in the Low Countries, called Gueldres-land, where it is 

 extremely abundant. V. lantana is the Mealy Gueldres Rose, 

 sometimes called Cotton Tree from its general mealiness. 



Viscous. Glutinous, sticky, like bird-lime. (L. viscum, the mistletoe, 

 a word also applied to bird-lime made from the berries of the 

 mistletoe). 



Weevils. A family belonging to the great order of beetles (Coleoptera). 

 They may generally be known by a snout or proboscis on the 

 head. 



Wings. Insects have normally two pairs of wings ; the Diptera and 

 others, however, have only one pair, while many are entirely 

 destitute of these appendages. When a single pair only is 

 present, it is almost invariably the first pair, and in Diptera, &c., 

 the hinder pair is represented by minute organs, called halteres, 

 balancers, or poisers. Wings vary much in texture, form, nature 

 of surfaces, and venation. As regards the first-mentioned character, 

 the greatest variations are exhibited by the first pair, and special 

 names have been applied to those wings presenting the variations 

 in a marked degree ; among these are the elytra. Development 



