GLOSSARY. 409 



GLAND. An organ which secretes or separates some peculiar product from the 



blood or sap of animals or plants. 



GLOTTIS. The opening of the windpipe into the oesophagus or gullet. 

 GNEISS. A rock approaching granite in composition, but more or less laminated, 



and really produced by the alteration of a sedimentary deposit after its 



consolidation. 

 GKALLATORES. The so-called "Wading-birds (Storks, Cranes, Snipes, &c.), 



which are generally furnished with long legs, bare of feathers above the 



heel, and hare no membranes between the toes. 



GRANITE. A rock consisting essentially of crystals of felspar and mica in a 

 mass of quartz. 



HABITAT. The locality in which a plant or animal naturally lives. 



HEMIPTERA. An order or sub-order of Insects, characterised by the possession 

 of a jointed beak or rostrum, and by having the fore-wings horny in the 

 basal portion and membranous at the extremity, where they cross each other. 

 This group includes the various species of Bugs. 



HERMAPHRODITE. Possessing the organs of both sexes. 



HOMOLOGY. That relation between parts which results from their develop- 

 ment from corresponding embryonic parts, either in different animals, as in 

 the case of the arm of man, the fore-leg of a quadruped, and the wing of a 

 bird ; or in the same individual, as in the case of the fore and hind legs in 

 quadrupeds, and the segments or rings and their appendages of which the 

 body oi a worm, a centipede, &c., is composed. The latter is called serial 

 homoiogy. The parts wnich stand in such a relation to each other are said 

 to be homologous, and one such part or organ is called the hamalogue of the 

 other. In different plants the parts of the flower are homologous, and in 

 general these parts are regarded^ as homologous with leaves. 



HOMOPTERA. An order or sub- order of Insects having (like the Hemiptera) a 

 jointed beak, but in which the fore- wings are either wholly membranous 

 or wholly leathery. The Cicadce, Frog-hoppers, and Aphides, are well-known 

 examples. 



HYBRID. The offspring of the union of two distinct species. 



HYMENOPTERA. An order of Insects possessing biting jaws and usually four 

 membranous wings in which there are a few veins. Bees and Wasps are 

 familiar examples of this group. 



HYPERTROPHIED. Excessively developed. 



ICHNBUMONID.K. A family of Hymenopterous insects, the members of which 

 lay their eggs in the bodies or eggs of other insects. 



IMAGO. The perfect (generally winged) reproductive state of an insect. 



INDIGENS. The aboriginal animal or vegetable inhabitants of a country or 

 region. 



INFLORESCENCE. The mode of arrangement of the flowers of plants. 



INFUSORIA. A class of microscopic Animalcules, so called from their having 

 originally been observed in infusions of vegetable mutters. They consist of 

 a gelatinous material enclosed in a delicate membrane, the whole or part of 

 which is furnished with short vibrating hairs (called cilia), by means of which 

 the animalcules swim through the water or convey the minute particles of 

 their food to the orifice of the mouth. 



INSECTIVOROUS. Feeding on Insects. 



INVERTEBRATA, or INVERTEBRATE ANIMALS. Those animals which do not 

 possess a backbone or spinal column. 



LACUNA. Spaces left among the tissues in some of the lower animals, and 

 serving in place of vessels for the circulation of the fluids of the body. 



