separated from Agaricus on account of 

 their peculiar habit, their waxy not mem- 

 branaceous gills, and granular intermediate 

 substance. Though the characters seem 

 rather indefinite, there is no difficulty in 

 recognising the genus at the first glance. 

 Many of the species are extremely beauti- 

 ful and exhibit the most brilliant colours, 

 but these are often not characteristic, the 

 same species presenting frequently very 

 different hues. A great many of them 

 grow in open pastures, and abound in the 

 fields in autumn, the woodland species 

 generally exhibiting a different type. All 

 of them readily imbibe and part with their 

 moisture, and several are covered all over 

 with a glutinous coat. Few, if any, are 

 admitted into our kitchens, though there 

 can be no doubt some are wholesome. H. 

 amicus is one of the commonest and most 

 variable species, exhibiting every shade 

 between yellow and scarlet ; it may, how- 

 ever, always be known by its turning black 

 when bruised. H. psittacinus presents va- 

 rious tints even in the same specimen ; it 

 is often extremely beautiful, its variety of 

 colours vying with those of parrots. The 

 genus is little known out of Europe and 

 the United States. [M. J. B.] 



HYGRORYZA. A genus of grasses, be- 

 longing to the tribe Oryzece, distinguished 

 by the spikelets being hermaphrodite, one- 

 flowered ; glumes two, the lower teraiinat- 

 ing in a tail-like bristle, the upper acute; 

 pales slender, toothed at the apex ; stamens 

 three ; styles one. H. aristata is a native 

 of the West Indies. [D. M.] 



HYGROSCOPICITY. The property of 

 extending or shrinking upon the applica- 

 tion or removal of water. 



HYMEN. In Greek compounds = a mem- 

 brane, or membranous. 



HYMENIUM. That part of hymenomy- 

 cetous fungals on which the spores are 

 borne— plates in Agaricus, tubes in Bo- 

 letus, &c. 



HYMENODES. Having a membranous 

 texture. 



HYMENOPHORUM. The pileus of cer- 

 tain fungals. 



HYMENULUM. A disk or shield con- 

 taining asci, but without excipulum. 



HYMESLEA. A genus of leguminous 

 plants of the section Ccesalpiniaz, so named 

 from Hymen, the god of marriage, in con- 

 sequence of the leaves being composed of a 

 pair of leaflets. Its flowers have a woody tu- 

 bular calyx with two bracts at its base, and 

 divided into Ave deciduous segments, the 

 two lower of which are sometimes joined 

 together ; and Ave unequal petals, inserted 

 along with the ten distinct stamens into 

 the summit of the calyx tube. The fruit 

 is a pod with a hard woody shell containing 

 several seeds imbedded in a fibrous pulpy 

 substance, which eventually becomes dry 

 and mealy, and is commonly eaten by 

 Indians. 



H. Courbaril, the common West Indian 



Locust tree, called Algarroba in Panama, 

 Jatai in Brazil, and Simiri in Guiana, is 

 a common tree in most parts of tropical 

 South America. It grows to an enormous 

 size, and, according to some calculations, 

 lives to a very great age, some of the trees 

 at present existing in the forests of Brazil 

 being supposed to have been of consider- 

 able size at the commencement of the 

 Christian era. Most of these old trees are 

 supported at the base by immense but- 

 tresses, and at this part some have been 

 measured no less than eighty-four feet in 

 circumference, while even at the top of 



Hymensea Courbaril. 



the buttresses, where the trunk assumes 

 the usual cylindrical form, the circumfer- 

 ence is as much as sixty feet. The timber 

 is of a fine brown colour, hard and close- 

 grained ; it is used for building and other 

 purposes in South America, and is occa- 

 sionally exported to this country. It is 

 covered with a very thick but light bark, 

 which is used by the Indians for making 

 canoes. A valuable resin, resembling the 

 anime of Africa, exudes from the trunk, 

 and large lumps of it are found about the 

 roots of old trees. [A. SJ 



HYMENANDRA. A genus of Myrsinacecp, 



consisting of a single species found in the 



Silhet district of India, and differing from 



the other genera in the anthers being 



united to each other by their margins, and 



in the ovaries containing numerous ovules. 



R. Wallichii is a stout evergreen shrub 



often cultivated in plant stoves for the 



sake of its handsome leathery and glossy 



I leaves, which are shortly stalked, and in 



| form and size a good deal like the leaflet of 



j ahorse-chestnut. The pretty pink flowers 



j disposed in compound lateral umbels 



j have wheel-shaped five-parted corollas half 



an inch across. The fruit is a berry about 



I the size of a pea. [A. A. B.] 



HYMENANTHERA. A genus of Austra- 

 lian shrubs, belonging to the violet family. 

 The leaves have no stipules; the flowers 

 are regular : the five short stamens arc 

 alternate with the petals, the anthers being 



