INDl] 



Elje Ereatfurg At 3&atmw. 



622 



edicts were issued prohibiting its xtse by 

 dyers, and stigmatising it us the devil's dye. 

 As met with in commerce at the present 

 day, Indigo usually consists of cubical 

 cakes, measuring between two and three 

 inches. It is prepared by throwing bundles 

 of the fresh-cut plants into shallow vats 

 and covering them with water, care being 

 taken to keep them under the surface. 

 After steeping for ten or twelve hours the 

 liquid is run off into another vat and 

 beaten with sticks or bamboos from one 

 and a half to three hours, in order to pro- 

 mote the formation of the blue colouring 

 matter, which does not exist ready formed 

 in the tissues of the plant, but is formed 

 by the oxidation of other substances con- 

 tained in them. The colouring matter is 

 then allowed to settle, the precipitation 

 being accelerated by the addition of a small 

 quantity of clean cold water or lime-water, 

 and the supernatant liquor drawn off and 

 thrown away, while the deposited matter is 

 put into a boiler and kept at the boiling 

 point for five or six hours. After this it is 

 spread upon frames covered with cloth, 

 and allowed to drain for twelve or fourteen 

 hours, and when it is sufficiently solid it is 

 pressed, cut into cubes, stamped and dried 

 for the market. Our imports of Indigo 

 average about 68,000 cwt. annually, the 

 greatest part coming from the East Indies, 

 but a large portion is re-exported to various 

 European countries, the consumption in 

 the United Kingdom not being more than 

 about 13,000 cwt. per annum. [A. S.] 



INDIGOTICUS. The deepest blue. 



INDIGOTIER. (Fr.) Indigo/era. 



INDIVISUS. Not separated into other 

 parts. 



INDRAJO'WJNDURJAW. Indian names 

 for the bitter seeds of Wrightia autidysen- 

 terica. 



INDUG A. An Indian name for the Clear- 

 ing-nut, Strychnos potatorum. 



INDUMENTUM. The hairy covering of 

 plants, of whatever kind. 



IXDUPLICATE, INDUPLIOATIVE. 



Having the margins bent abruptly in- 

 wards, and the external face of these edges 

 applied to each other without any twist- 

 ing. 



IXDURASCENT. Hardening by degrees, 

 as the permanent petioles of a tragacanth 

 bush. 



INDUSIUM. A name given to the im- 

 mediate covering of the tuft of capsules or 

 sporangia in ferns. Sometimes the sori 

 are quite naked, the cuticle bein? simply 

 ruptured by the protrusion of the young 

 fruit. Sometimes, however, the cuticle is 

 lifted up, and forms a covering of various 

 shapes, \mns sometimes lateral, sometimes 

 target-shaped, sometimes spherical, &c. 

 In other cases the indusium appears to be 

 a distinct growth arising from the tip or 

 side of a vein. The border is either entire 

 or ciliate. The indusium may be variously 



seated even in the same genus, or again it 

 may be almost obsolete, or, as in Hypolepis 

 tenuifolia, be quite membranous or herba- 

 ceous, and in the latter case partaking 

 more of the nature of the frond itself. 

 In Pleopeltis, the indusium is replaced by 

 a number of peltate scales, which, however, 

 have no real relation to a true indusium. 

 In genera like Hymenophyllum, where 

 the fruit is produced at the tip of the pro- 

 truding costa, the bivalvate or cup-shaped 

 indusium is either formed of the frond 

 itself, or springs from the excurrent costa. 

 Sometimes the sori are covered, not only 

 with an indusium, but with a portion of 

 the turned-upedge of the leaf. The annu- 

 lus of some fungals also bears the same 

 name. [M. J. B.] 



INDUVI^E (adj. INDUVIATE). Wi- 

 thered leaves remaining upon a stem, 

 and clothing it. 



INENCHYMA. Fibro-cellular tissue, 

 that is to say, cells having the appearance 

 of spiral vessels. 



INERMIS. Destitute of any kind of 

 spines or prickles. 



INFERIOR. Growing below some other 

 organ ; thus, an inferior calyx grows below 

 the ovary, whilst an inferior ovary grows, 

 or seems to grow, below a calyx. 



INFLATED. Thin, membranous, slightly 

 transparent, swelling equally, as if inflated 

 with air. 



INFLORESCENCE. The manner in 

 which the flowers are arranged. 



INFOSSOUS. Sunk in anything, as veins 

 in some leaves, leaving a channel, how- 

 ever. 



INFRACTOUS. Curved inwards. 



INFUNDIBULAR, INFUNDIBULP 



FORM. Funnel-shaped. 



INFUNDIBULI-CAMPANULATE. Be- 

 tween funnel-shaped and bell-shaped. 



INGA. A very extensive genus of legu- 

 , minous plants, of the section Mimosea?, 

 ! comprising nearly one hundred and fifty 

 species, ail of which are natives of the 

 warmer parts of South America, princi- 

 pally of Brazil and Guiana. They form 

 large shrubs or trees, sometimes growing 

 fifty or sixty feet high, and have pinnate 

 leaves composed of from two to five or 

 six pairs of largish leaflets, bearing a gland 

 on the stalk between each pair, the stalk 

 being frequently winged or leaf-like. The 

 flowers are usually white or yellowish, and 

 borne in variously shaped spikes or in 

 nearly globular heads, growing singly or 

 in clusters from the angles of the leaves. 

 They are generally all perfect, and have a 

 tubular calyx, and a tubular or funnel- 

 shaped corolla, enclosing an indefinite 

 number of stamens, which are twice or 

 several times the length of the corolla, and 

 joined together at the bottom. The pods 

 are flattened or roundish, with thickened j 



