330 UMBELLIFER^. 



apart. The plant is cut with sickles, and when dry the seed is thrashed 

 out on a cloth in the centre of the field. On the best land, 15 cwt. per 

 acre is reckoned an average crop.^ 



Description — The fruit of coriander consists of a pair of hemi- 

 spherical mericarps, firmly joined so as to form an almost regular globe, 

 measuring on an average about 4 of an inch in diameter, crowned by 

 the stylopodium and calycinal teeth, and sometimes by the slender 

 diverging styles. The pericarp bears on each half, 4 perfectly straight 

 sharpish ridges, regarded as secondary (juga secundaria) ; two otber 

 ridges, often of darker colour, belonging to the mericarps in common, 

 the separation of which takes place in a rather sinuous line. The 

 shallow depression between each pair of these straight ridges is occu- 

 pied by a zig-zag raised line (jugum pHmarium), of which there are 

 therefore 5 in each mericarp. It will thus be seen that each mericarp 

 has 5 (zig-zag) so-called primary ridges, and 4 (keeled and more pro- 

 minent) secondary, besides the lateral ridges which mark the suture 

 or line of separation. There are no vittse on the outer surface of the 

 pericarp. Of the 5 teeth of the calyx, 2 often grow into long, pointed, 

 persistent lobes ; they proceed from the outer flowers of the umbel. 



Though the two mericarps are closely united, they adhere only by 

 the thin pericarp, enclosing when ripe a lenticular cavity. On each 

 side of this cavity, the skin of the fruit separates from that of the seed, 

 displaying the two brown vittse of each mericarp. In transverse sec- 

 tion, the albumen appears crescent-shaped, the concave side being 

 towards the cavity. The carpophore stands in the middle of the latter 

 as a column, connected with the pericarp only at top and bottom. 



Corianders are smooth and rather hard, in colour buff or light brown. 

 They have a very mild aromatic taste, and, when crushed, a peculiar 

 fragrant smell. When unripe, their odour, like that of the fresh plant, 

 is offensive. The nature of the chemical change that occasions this 

 alteration in odour has not been made out. 



The Indian corianders shipped from Bombay are of large size and of 

 elongated form. 



Microscopic Structure — The structural peculiarities of coriander 

 fruit chiefly refer to the pericarp. Its middle layer is made up of thick 

 walled ligneous prosenchyme, traversed by a few fibro- vascular bundles 

 which in the zig-zag ridges vary exceedingly in position. 



Chemical Composition — The essential oil of coriander has a com- 

 position indicated by the formula C^'^ff^O, and is therefore isomeric 

 with borneol. If the elements of water are abstracted by phosphoric 

 anhydride, it is converted, according to Ka waller (1852), into an oil of 

 offensive odour, C^'^H^*'. 



The fruits yield of volatile oil from 07 to 11 per cent. ; as the vittse 

 are well protected by the woody pericarp, corianders should be bruised 

 before being submitted to distillation. Trommsdorff (1835) found the 

 fruits to afford 13 per cent, of fixed oil. 



The fresh herb distilled in July when the fruits were far from ripe, 



yielded to one of us (F.) from 0-57 to 11 per mille of an essential oil 



possessing in a high degi'ee the disagreeable odour already alluded to. 



This oil was found to deviate the ray of polarized light 11° to the right 



iR. Baker, in Morton's Cyclopaedia of Agriculture, i. (1855) 545. 



