AN ENCYCLOPEDIA OF HORTICULTURE. 



189 



Insects continued. 



membranous, and hidden tinder the front ones. The latter 

 have the half nearer the body leathery, that farther from 

 the body membranous, giving the appearance of the wings 

 being in halves, whence the name Hemiptera, or half- 

 winged insects. The name Heteroptera refers to the 

 dissimilar appearance of the two halves. In this sub- 

 order, many of the species are more or less parasitic; 



Fro. 314. FROG HOPPER, showing Larva, Frothy Secretion, 

 and perfect Insect. 



while among those that feed on plants, there are few that 

 can be said to be conspicuously hurtful. 



Homoptera have the wings all membranous and naked, 

 with few supporting nervures, and often resemble small 

 Hymenoptera in general aspect (see Fig. 313). A great 

 many species are wingless, or, at least, have wing- 



Inula continued. 



herbaceous plants, natives of Europe, Asia, and Afrie 

 few being found between the tropics. Flower-heads yellow ; 

 rays rarely white; involucre hemispherical, imbricated, 

 with the scales spreading at the points; ray-florets 



Fio. 315. GRAPE OR VINE LOUSE, showing (A) Infested Vine 



Root ; (B) Portion of Leaf, with Galls ; (c) Subterranean Form 



of Female (magnified). 



less individuals as well as winged (see Figs. 313 and 

 315). The name Homoptera refers to the front wings 

 being alike throughout (see Figs. 313 and 314). The 

 insects are mostly very small, but include many injurious 

 forms. See also Aphides, Frog Hopper, Grape 

 Louse, and Scale Insects. 



INSECTS, FERTILISATION BY. See Fer- 

 tilisation by Insects. 



INTEGERRIMUS. Entire; perfectly free from 

 division of the margin or other part. 



INTER/NODES. The intervening space between two 

 nodes. 



INTERFETIOLAR. Between the petioles. 



INTERRUPTED. Not continuous. 



INTRORSE. Turned towards the axis to which it 

 appertains ; e.g., an anther when its valves face the centre 

 of a flower. 



INT7LA (the old Latin name used by Horace, &c., 

 said to be another form of Helenion). ORD. Composite. 

 A genus comprising about fifty-six species of hardy 



FIG. 316. INULA GLANDULOSA. 



numerous, ligulate, linear; disk-florets very numerous, 

 perfect, tubular ; receptacle flat, or nearly so, areolate or 

 honeycombed. Leaves radical or alternate, entire or 



FIG. 317. INULA HELENIUM. 



serrate. Only a few species of this genus are worth 

 growing. They are of very easy culture in common 

 garden soil. Some of the more vigorous are suitable for 



