Page:The American Cyclopædia (1879) Volume VIII.djvu/644

 630 IIEMLING HEMLOCK SPRUCE have the habits of the harvest flies, but they make no drumming sound, and leap and fly to a considerable distance, even to 250 times their length ; they pass their time on plants, always placed lengthwise of the limbs, with the head toward the end of the branches ; from their 1, i Tree Hopper (Membracis). 8. "Water Scorpion (Kepa). conical shape, dark color, and fixed position, they look much like the thorns of a tree ; lo- cust and oak trees and many vines suffer from the abstraction of their sap by these insects and from the injury done to their leaves. Tree hoppers are often surrounded by ants, for the Bake of their droppings or for the sap which oozes from their punctures. The frog hoppers (cercopis, Fab.) possess still greater leaping powers; the larva extract the sap of alders, willows, &c., in such quantity that it oozes from their bodies continually in little bubbles, whose white foam completely covers them du- ring the period of their transformation ; this is called frog spittle and cuckoo spittle. The leaf hoppers (tettigonia, Geoffr.) are very small, but handsome, agile, and destructive to vege- tation; vines, rosaceous plants, beans, &c., suffer much from their exhausting punctures ; tobacco fumigations and the application of whale-oil soap in solution are the best reme- dies. Some plant lice have the power of leap- ing, though both sexes, when mature, are winged ; these belong to the genus psylla (Geoffr.), live on pear and other trees, sucking the juices of the young twigs, and are far less prolific than the aphides; these sap suckers are attended by swarms of ants and flies, at- tracted by the sweet fluid which flows from their bodies ; young trees are often killed by them. From the family coccida are obtained the scarlet grain and cochineal of commerce, now ascertained to be insects or bark lice of the genus coccus (Linn.) (see COCHINEAL) ; the mealy bug of our greenhouses is the C. Adoni- dum ; the C. hesperidum infests the myrtle. These lice are destroyed by the wren, chick- adee, and ichneumon flies; strong soap and alkaline solutions will also kill them. HEM LING. See MEMLING. HEMLOCK, a name applied to conium macu- latum (see COXIUM) and cicuta maculata (see CICUTA), as well as to abies Canadensis (see HEMLOCK SPRUCE). It is probable that the hemlock or Kuveiov which caused the death of Socrates was identical with the plant now known as conium. HEMLOCK SPRITE, the common name of the tree able* Canadensi*, of the order conifera, which is quite as frequently called hemlock simply. The hemlock spruces mainly differ from the spruces proper in having flat two- ranked leaves, and the cells of the anthers opening transversely instead of lengthwise; from the firs they differ in having persistent cones and in the wing of the seed remaining attached to it; while in the firs the scales faU from the axis of the cone and the seed sepa- rates from its wing. On account of these differences Carrire proposed to place the hem- lock spruces in a separate genus, to which he gave the barbaric name tiuga ; botanists do not accept his views, and regard the firs (picca), the spruces (abie* and the hemlock spruces (tsuga) as subgenera of abitt. The hemlock spruce is essentially a northern tree. Making its appearance in the southern states only on the mountain ranges, it increases in frequency toward the northern borders of the United States, where large forests of it are not rare, while in Canada it covers vast tracts often without the presence of any other species, and extends to the northernmost limits of arbo- rescent vegetation, and across to the Pacific. It grows in almost every situation except in a very dry one. The hemlock spruce is one of the finest of our native conifers, reaching the height of 60, 80, and not rarely 100 ft. ; when it occurs as a solitary specimen, it appears as a fine pyramid of verdure, being furnished Hemlock Spruce (Abies Canadensis). from the ground to the top with long grace- in the forest the straight trunk is without, The smaller branches and twigs are very I slender ; the leaves, about half an inch long
 * fully drooping branches; but when it grows
 * branches for the greater part of its length.