212 



SCIENCE OF AGRICULTURE. 



Part II. 



generally adopted division of imperfect plants is that by which they are distributed into 

 i^ilices, ^quisetaceae, Lycopodineae, JVfusci, Hcpatica?, A'lgse, iichenes, and i^ungi. 



1329. The Fih'ces, 'Equi'setdcea;, and Iji/copodinete are for the most part herbaceous, and die down to the 

 ground in the winter ; but they are furnished with a perennial root, from which there annually issues a 

 frond bearing the fructification. The favourite habitations of many of them are heaths and uncultivated 

 grounds, where they are found intermixed with furze and brambles ; but the habitations of such as are 

 the most luxuriant in their growth are moist and fertile spots, in shady and retired situations, as on 

 mossy dripping rocks, or by fountains and rills of water. Some of them will thrive even on the dry and 

 barren rock, or in the chinks and fissures of walls ; and others only in wet and marshy situations where 

 they are half immersed in water. 



1330. The Mfisci {Jig. 179. a b) form a tribe of imperfect plants of a diminutive size, often consisting 

 merely of a root, surmounted with a tuft of minute leaves, from the centre of which the fructification 

 springs ; but furnished for the most part with a stem and branches, on which the leaves are closely imbri- 

 cated, and the fructification terminal or lateral. They are perennials and herbaceous, approaching to 

 shrubby ; or annuals, though rarely so, and wholly herbaceous, the perennials being also evergreens. 



1331. The Hepdtiae (fig. 179. c) form a tribe of small herbaceous plants resembling the rrwsses, but 

 chiefly with frondose herbage, and producing their fruit in a capsule that splits into longitudinal valves. 

 In their habitations, they affect for the most part the same sort of situations as the mosses, being found 

 chiefly in wet and shady spots, by the sides of springs and ditches, on the shelving brinks of rivulets, 

 or on the trunks of trees. Like the mosses, they thrive best also in cold and damp weather, and recover 

 their verdure though dried, if moistened again with water. 



1332. The K'lgce, or sea-weeds, include not merely marine and many other submersed plants, but also a 

 great variety of plants that are not even aquatics. All the ^'Igas agree in the common character of having 

 their herbage frondose, or but rarely admitting of the distinction of root, stem, and leaf. 



1333. The utility of the K'tgcB is obviously very considerable, whether we regard them as 

 furnishing an article of animal food, or as appli- 

 cable to medicine and the arts. The Laminaria 

 saccharina {^jig. 1 SO a), HaJym^nia palmata(6) and 

 ediilis (c), and several other Fuci, are eaten, and 

 much relished by many people, whether raw or 

 dressed; and it is likely that some of them are fed 

 upon by various species of fish. The J^ucus Zi- 

 chenbides [Turner, c. 118.) is now believed to be 

 the chief material of the edible nests of the East 

 India swallows, which are so much esteemed for 

 soups, that they sell in China for their weight in 

 silver. [Far. Mag., vol. xx.) When disengaged 

 from their place of growth and thrown upon the 

 sea-shore, the European A'lgse are often collected 

 by the farmer and used as manure. They are 

 also often employed in the preparation of dyes, 

 as well as in the lucrative manufacture of kelp, a 

 commodity of the most indispensable utility in 

 the important arts of making soap and glass. 



1 334. The utility of the Lichenes is also worthy of notice. The ilchen rangifennus forms 

 the principal nourishment of the reindeer during the cold months of winter, when all 

 other herbage fails. The Xichen isldndicus is eaten by the Icelanders instead of bread, 

 ot used in the preparation of broths ; and, like the Ziehen pulmonarius, has been lately 

 found to be beneficial in consumptive affections. Many of them are also employed in 

 the pre^ation of some of our finest dyes or pigments ; and it is from the Lecanora parel- 

 la that 1^ chemical analyst obtains his litmus. The lichens and the mosses seem in- 

 stituted by nature to provide for the universal diffusion of vegetable life over the whole 

 surface of the terrestrial globe. The powdery and tuberculous lichens attach themselves 

 even to the bare and solid rock. Having reached the maturity of their species, they die 

 and are converted into a fine earth, vehich forms a soil for the leathery lichens. These 

 again decay and moulder into dust in their turn ; and the depth of soil, which is thus 

 augmented, is now capable of nourishing and supporting other tribes of vegetables. The 

 seeds of the mosses lodge in it, and spring up into plants, augmenting also by their decay 

 the quantity of soil, and preparing it for the support of plants of a more luxuriant growth, 



