TH 



587 



T HU 



a vine may be taken, when ripe, at half the leaves, and at this time the recently 

 a pound each, and with this data it is hatched but perfect insect, either lies 

 easy to carry into practice Mr. Clement close under the ribs, or roves about in 



Iloare's excellent rule for proportioning 

 the crop to the size of the vine. 



If its stem, measured just above the 

 ground, be three inches in circumfer- 

 ence, it may bear five pounds weight of 

 grapes. 



3.i inches 10 lbs. 



4 '• 15 " 



41 " 20 " 



5" " 25 " 



And so five pounds additional for 

 every half inch of increased circum- 

 ference. 



Thinning is a most necessary opera- 

 tion with |)lanls, as well as with the 

 fruit they bear. The roots of a plant 

 extend in a circle round it, of which the 

 stem is the centre. If the roots of ad- 



search of a mate." — Gard. Chron. 



T. ochraceiis infests the ripe fruit of 

 plums, peaches, and nectarines, pierc- 

 ing the stalks and causing their fall, and 

 rendering the fruit disgusting. It was 

 first noticed, and thus described by Mr. 

 Curtis : — 



'• It is narrow and linear, of a bright 

 and deep ochreous colour, the eyes are 

 black, the horns appear to be only six- 

 jointed and brownish at the tips ; it has 

 three ocelli in the crown, the body is 

 hairy, the tip pointed and bristly, the 

 wings are shorter than the body in the 

 male, lying parallel on the back when 

 at rest, narrow, especially the under 

 ones, and fringed, the hairs longest 

 eneath and at the point, tips of feet 



joining plants extend within each other"s dusky." — Gard. Chron. 



circle, they mutually rob of nutriment, 

 and check each other's growth. Thin- 

 ning in the seed-bed is the remedy 

 generally applied with too timid a 

 hand. 



TMOMASIA. Seven species. Green- 

 house evergreen shrubs. Ripe cuttings. 

 Loam, peal, and sand. 



THOU INI A pinnata. Stove ever- 

 green shrubs. Ripe cuttings. Sandy 

 loam and peat. 



T H R I F T. Statice armeria. See 

 Edgings. 



TflKIPS, a genus of predatory in- 

 sects. 



T. adonidum is particularly injurious 



THROATWORT. Campanula cervi- 

 caria. 



THROATWORT. Campanula tra- 

 chelium. 



THROATWORT. Trachelium. 



THRYALLIS brachystachys. Stove 

 evergreen climber. Ripe cuttings. 

 Loam and peat. 



THUJA arbor vitcB. Eight species. 

 Evergreen trees, all hardy except T. 

 articulata, which is half-hardy, and T. 

 cupressoides ,\wh\ch belongs to the green- 

 house. Seeds, and T. pendula, one of 

 the rarer kinds, by cuttings. A moist 

 soil suits them best. T. occidentalis 

 and T. orientalis form admirable ever- 



to stove plants. Its different forms are green hedges, and when properly shear- 

 ed, inclining inward from the base so 

 that no part is overshadowed, retain 

 their beauty for many years. As a 

 standard, the occidentalis or American 

 arbor vitT, has few superiors among the 

 minor evergreens. 



THUNBERGIA. Ten species. Stove 



thus j)ortrayed by that excellent ento 

 mologist, Mr. Curtis : — 



" Tlie larva; and pupa; are yellowish- 

 white, and the perfect insect is of a 

 dull deep black, with the point, and 

 sometimes the whole of the abdomen, 

 of a rust colour, the wings are dirty 



white, the horns and legs yellowish, I evergreen climbers, except T. auran- 



the extremity of the former black ; it is 

 very troublesome in hot-houses, attack- 

 ing tropical plants by piercing the under 

 side of the leaves, and one often sees 

 at the tip of the tail a globule of black- 

 ish fluid, which it soon deposits, and by 

 innumerable spots of this glutinous mat- 



tiaca, a green-house herbaceous peren- 

 nial. Cuttings or seeds. Sandy loam 

 and leaf mould. 



Mr. Maclntyre says, that the species 

 of this genus, " tho'ugh usually grown 

 in a stove, will flower freely in a green- 

 house, or even when they are planted 



ter the pores of the leaves are stopped out in the open border, during the sum- 

 up, and large portions of the surface ' mer months: if the situation is sheltered, 

 become blotched. During March the and exposed to the influence of the sun, 

 full-grown larva; and pupx^ which are | they will flower well. In propagatmg 

 as large as the perfect insect, are found 1 those that are intended for planting out, 

 in groups, feeding on the under side of i take ofT the lateral shoots when they are 



