HEMIPTERA 



2766 



HEMLOCK 



It is of a brownish-red, reddish or black color, 

 but when scratched gives a blood-red streak, 

 hence its name, which means bloodlike. Hema- 

 tite occurs in almost all forms, from solid rock 

 to loose earth. Some of the harder forms take 

 a high polish and reflect light, like a mirror, 

 therefore are called specular iron. An earthy 

 variety constitutes the pigment, red ocher. But 

 the great mass of hematite is valuable as the 

 source of iron. In America this ore occurs in 

 immeasurable quantities around the head of 

 Lake Superior in Wisconsin and Minnesota, in 

 Alabama and at Iron Mountain, Mo. See 

 IRON, for details of wider distribution. 



HEMIPTERA, hemip'tera, a large group 

 of insects popularly known as bugs. The word 

 is derived from words meaning half a wing, and 

 refers to the thick base and abruptly-thin tip 

 in the most common species. The hemiptera 

 differ from other orders of insects in two re- 

 spects. First, the mouth-organ, called the ros- 

 trum, consists of a horny, jointed, tapering 

 tube, which is adapted for piercing the tissues 

 of plants or the skins of animals. By the aid 

 of contractile muscles it sucks the juices from 

 plants and the blood from animals. Second, 

 the organs of flight, the fore wings, and the 

 hinder parts, or wings proper, are thick and 

 leathery at the base, and membranous at the 

 tip. Certain forms, such as the bedbug and 

 louse, have no wings; the water bugs may be 

 entirely unwinged, half winged or fully winged. 

 See ZOOLOGY. 



Consult Comstock's Manual for the Study of 

 Insects; Foot's Insect Wonderland; Howard's 

 The Insect Book. 



Related Subjects. The following important 

 members of the order Hemiptera are given sepa- 

 rate treatment in these volumes : 

 Aphides Louse 



Bedbug Mealy Bug 



Chinch Bug San Jose Scale 



Cicada Scale Insect 



Jigger Ticks 



HEMISPHERE, hem'isfeer, literally halj a 

 sphere, is a term particularly applied to one 

 of the halves into which the globe is divided 

 by geographers. The eastern hemisphere, or 

 Old World, embraces Europe, Asia, Africa and 

 Australia; north and South America are in- 

 cluded in the western hemisphere, or New 

 World. The boundary is not fixed by geo- 

 graphical or political considerations, but runs 

 rather indefinitely from pole to pole through 

 the North and South Atlantic and the Pacific 

 oceans. The division of the earth's surface 

 into northern and southern hemispheres is 



natural, the equator, in the exact center, form- 

 ing the dividing line. 



HEMISPHERES 



Above, western and eastern, the New World and 

 the Old World, respectively ; below, northern and 

 southern. 



HEM 'LOCK, a poisonous plant with leaves 

 so like those of parsley that it is often mis- 

 taken for the latter plant. It grows to a height 

 ranging from two to six feet, with hollow stems, 

 many branches, and numerous clusters of small 

 white flowers. The plant has a disagreeable, 

 nauseous odor, which becomes very strong 

 when the leaves or stems are bruised. This 

 affords a sure and quick means of distinguish- 

 ing between hemlock and parsley. The hem- 

 lock bears an egg-shaped fruit about one-eighth 

 of an inch in length, which ripens in August 

 or September. The leaves and fruit are used 

 for medicinal purposes, chiefly on account of 

 the soothing action of the drugs they contain. 

 The poison hemlock is a native of Great Brit- 

 ain, Europe and some parts of Asia, and has 

 been naturalized in North America and Chile. 

 It grows chiefly on low-lying, marshy ground. 

 Socrates, the Greek philosopher, and Phocion, 

 the Athenian general, died after drinking a 

 brew of poison hemlock. 



HEMLOCK, or HEMLOCK SPRUCE, so 

 called because of botanical resemblance to the 

 hemlock plant (see preceding article). It is 

 a large tree, growing to a height of seventy or 

 more feet, and is found in the forests of Canada 

 and the United States. There are four distinct 

 species, but the most useful is the eastern hem- 

 lock, technically named Tsuga Canadensis, 

 which is found in Eastern Canada and in the 

 United States as far west as Minnesota and 



