278 GLOSSARY 



limes more than 30,000 are present. In true larvae these eyes are 

 wanting. 



Eyes, simple. Usually termed ocelli. Possessed by many adult 

 insects in addition to their compound eyes, between which they 

 are situated, on the crown of the head. Vary in number, but are 

 usually three. Each resembles a small separate eye of the com- 

 pound eye. In all insects that undergo a true metamorphosis, 

 ocelli are the only organs of vision in the larval state. In that con- 

 dition there may be several, and they are fixed on the sides of the 

 head. 



Fades. Appearance, aspect. 



Family. A group of genera having structural features in common, by 

 which they resemble one another, and differ from all other genera. 

 A group of families, similarly associated, constitutes an Order ; a 

 group of species, a Genus. 



Feelers. Or palpi, jointed organs, appended to the lesser jaws and in- 

 ferior lip of the mouth in insects. 



Fibro-vascular bundles. See Parenchyma. 



Filament. A slender thread-like body. 



Formicites. Ants may be divided into three groups, characterised by 

 somewhat important structural differences, viz., Formicites, 

 Ponerites, and Myrmicites. 



Fossorial. Having a power of digging. 



Fuliginous. Of the colour of dark smoke. 



Fungus, pi. fungi. A class of cellular plants. Mushrooms and 

 Moulds are common examples. 



Fuscous. Of a dark or blackish brown. 



Fusiform. Shaped like a spindle ; gradually tapering at each end. 



Gallic. Denoting the acid obtained from galls. 



Galls. Excrescences, chiefly on the oak, caused principally by the 

 puncture and deposited eggs of the family Cynipidoe. 



Ganglion. A swelling or knot on nerves, a nerve centre containing 

 nerve cells, and receiving and giving out impressions. 



Genus. A group formed by a number of species having characters 

 in common. 



Glumes. The scaly bracts of grasses and sedges. 



Gullet, or oesophagus. Extending into and through the thorax, is the 

 upper or narrowest portion of the alimentary canal, or passage 

 down which food and drink pass from the mouth in animals. 



Halteres, balancers or poisers. Appendages in two-winged flies, believed 

 to represent the absent hinder wings. See Diptera. In the males 

 of Coccidae, which also possess only the first pair of wings, the 

 halteres probably aid in flight. 



Haustellate. Furnished with a sucker. 



Haustellum. A sucker. The term is applied to various forms of 

 insect-mouths adapted for suction. 



Head. The first of the three regions into which the body is divided. 

 Like the other regions, it is believed to be formed of several 

 segments, grown or fused together into one mass. The typical 

 body-segment possesses a single pair of legs only. Certain mouth- 



