Page:The American Cyclopædia (1879) Volume X.djvu/548

 542 LIVERWORTS of England brought him at the outset consid- erable popularity; but the distresses which followed after the war, and the severe mea- sures adopted to repress internal disturbances, subsequently aroused against him a strong feel- ing of dislike, which was increased by the in- troduction of the bill of pains and penalties against Queen Caroline. To liberal opinions he was always steadfastly opposed, and his efforts, extending over a period of more than 30 years, greatly contributed to retard Catholic emancipation, parliamentary reform, the eman- cipation of the slaves in the West India colo- nies, and other kindred measures. His pri- vate character was above reproach, and few ministers holding such extreme views have been more respected by political adversaries. He was attacked by paralysis, Feb. 17, 1827, and passed the last three months of his life in a state of helplessness and imbecility. LIVERWORTS, a family of cryptogamous plants, called hepaticce by botanists. The liv- erwo'rts are humble, often very minute plants, in some genera resembling the lichens and in others the mosses, from both of which they differ in their organs of reproduction. In some genera the vegetative portion t>f the plant is frondose, consisting of a leaf -like ex- pansion of very loose cellular tissue, which spreads upon the ground and emits rootlets from its under surface ; this is variously lobed or forked ; in other genera there is a distinct stem, bearing true leaves in two rows, and there is often on the under side of the stem a row of rudimentary stipule-like leaves (amphi- gastria) ; the leaves are entire, toothed, lobed, or even deeply divided, and the form and markings of these as well as of the amphigas- tria being very constant in each genus and species, they afford characters by which the plants may be distinguished when the fructi- fication is wanting. The reproductive organs are of two kinds, corresponding in their office to the stamens and pistils in the higher orders of plants ; these are monoecious or dioecious, are sometimes sunk within the substance of the frond as in Riccia, sometimes above it, or, as in Marchantia, elevated upon a pedicel. The an- theridia, or male organs, consist of numerous oblong or spherical sacs, which when ripe rupture and liberate their contained cells, which in a short time emit the antherozoids, minute filiform bodies which bear at one ex- tremity two still smaller threads. The pistil- late organs, termed pistillidia or archegonia, after receiving the action of the antherozoids, increase in size and form the sporangia or the true fructification ; these open usually by four valves to discharge their spores, the true re- productive bodies; the spores are contained in fours in mother cells ; their dissemination is often aided by elongated cells, the elaters, which are capable of a spirally twisting move- ment. The capsule or sporangium is usually surrounded by a tubular organ, the perianth, and this again by an involucre, also tubular, or leaves of a peculiar form. Besides this sexual reproduction, liverworts are often multiplied by bulbils, which are variously shaped cellular bodies, capable of growing and producing a plant; these bulbils are in the marchantias produced in little cups, elegantly fringed on Eiccia natans. 1. The Plant. 2. Magnified Section. 3. Ca- lyptra and Spores. their edges, which are situated upon the upper surface of the fronds ; in other genera they are produced in different parts of the plant. The large family of the liverworts is divided into suborders. Berkeley, who is an author- Marchantia polymorpha. 1. Female Plant. 2. Male Plant with cupule. 3. Elater and Spores. ity in cryptogamic botany, makes three, which he thinks should rank as natural orders: 1, the Ricciacece, which consists of a few chiefly floating frondose plants, which produce root- lets from beneath, and have their organs of fructification sunk in the frond, or sometimes