MOSSAMEDES 



MOSTAGANEM 



327 



Mossainedes, a seaport on Little Fish Bay, in 

 Angola, the Portuguese territory on the West 

 Coast of Africa. Pop. 2000. 



Mosses (Musci). The mosses are a class of 

 small flowerless plants, important in the economy 

 of nature, and of great interest in their life-history. 

 They are found in all climates, but are most abund- 

 ant in temperate regions ami in damp places. They 

 are included with the Liverworts in the division 

 Mnscinere, which U sharply separated from the 

 higher division of Vascular Cryptogams (Kerns, 

 &c. ) by the alence of vessels ; while the lower 

 members of the group consist of a mere flat thallus, 

 and are thus related to the Thallophytes. This, 

 with other characters, indicates that the Muscineje 

 form an independent branch of the tree of evolution, 

 and are not an intermediate type. 



The uses of mosses in medicine and the arts are 

 few and unimportant, but in mountain-regions the 

 thick felts of moss and deep beds of peat soak np 

 the rain, and so prevent Howls from sudden storms, 

 and in dry weather supply the streams through 

 weeks of drought. With favouring surroundings 

 tlie life of a moss-plant seems to be endless ; the 

 mosses (Sphagnum) we see growing to-day in a 

 bog are the tips of plants which began life perhaps 

 thousands of years ago, and which have formed a 

 great bed of peat, which may be 20 feet thick. 

 This social habit of moss is a peculiarity. In some 

 species cushions of marvellous regularity are formed ; 

 it enables individual plants to stand erect, and i- of 

 great importance in the process of fertilisation. 

 The capsules of many mosses must be familiar to 

 every one as small sacs at the ends of their hair- 

 like stalks, which rise in great numbers from a 

 moss-cushion. These contain the spores, from each 

 of which when sown there grows in a few days a 

 tiny thread-like plant, the protonema. Buds of 

 young moss-plants soon appear on this, and then, 

 aa a rule, tne thread-plant dies. A moss-plant 

 consists of a stem with leaves and roots. The 

 roots will grow out from any part of the plant that 

 is kept dark and damp ; they are very like the 



Diagram of the Life-history of a Moss : 

 a, spore ; b, spore producing the thread-like underground proto- 

 nema; c, bud from protnnema which will rise into mo8H- 

 plant ; ft, a leaf-bearing portion of moss-plant : e, apex oi 

 mofu-plant with club-shap^l mule organs (antheridla) pro- 

 ducing male cell*, one of which lien between < and /; /, a|*x 

 of moss-plant with bottle-shaped female organs (arcli. ^"111.1 

 within which is the female cell ; j, (/, Bpore-producing genera- 

 tion which KVOWI from diviaiun of fertilised egg-cell and upon 

 the female plant. 



protonema, indeed buds of new plants may arise 

 on them. Even from a detached leaf roots ami new 

 plants will grow ; this is a sign of the simple 

 nature of the tissues. By their branching habit, 

 and by the death of the older parts, which leave 

 the branches as separate plants, and in many species 

 by the growth of special buds which are easily 

 separated from the parent, mosses are rapidly pro 



>agated, indeed in many species the production of 

 spores is rare. The sexual mode of reproduction is 

 as follows. At the apex of a plant about mid- 

 summer may often be seen what are popularly 

 iiiown as moss flowers. These consist of a rosette 

 of numerous leaves, smaller than ordinary, a sort 

 of bud in fact. In the centre are male and female 

 organs (antheridia and arcliegonia ), but in some 

 species the male are on one plant, the female on 

 another ; within the 'flowers' are also barren leaves 

 known as uaraphyses. The antheridia are club- 

 shaped bodies ; when ripe, if they are wetted, they 

 burst ; the contained cells are squeezed out as a 

 gelatinous mass ; within each cell is a small motile 

 ' antherozoid ; ' this, owing to the nearness of the 

 plants to one another, is able to swim away if the 

 moss is thoroughly wet. The arcliegonia are flask- 

 shaped ; within them lies, in the bottom of the flask, 

 thelarge egg-cell ; in the neck a row of 'canal cells;' 

 these, when the egg-cell is ready, swell up and form 

 a jelly. If an antherozoid is near, it enters the 

 jelly, and working down to the egg-cell fertilises 

 it. The ovum now grows within the flask, which 

 for a time grows with it, forming the 'calyptra;' 

 but after a time the flask is split, and the growing 

 embryo forces its way down into the parent pliant, 

 and is nourished by it. When fully grown it is the 

 capsule containing spores, of which we have already 

 spoken, and thus the life-cycle of the moss is com- 

 pleted. This cycle consists of two generations, the 

 moss-plant which produces an egg ; from the egg 

 grows a plant which produces spores, but itself 

 remains attached to the parent plant. This is 

 called an alternation of generations. The fern has 

 a similar story, but in this case the (pore-bearing 

 generation is the com p'cuous plant. Fossil remains 

 have been found in rocks of .Palaeozoic age. 



Classification. There are some 3000 species ; these 

 are divided into four orders. ( 1 ) Bryacea-, which 

 include the vast majority of genera. The sporan- 

 gium always has a cap, 'calyptra,' which, when 

 ripe, is blown away by the wind ; beneath this is 

 a lid, ' operculum,' which splits off from the capsule, 

 exposing the spores. The capsule has a long stalk, 

 'seta.' The commonest forms are Funaria, Poly- 

 trichum, &c. (2) Phascacea-, a small order; the 

 spores are set free by the rotting of the sporan- 

 gium ; the protouema persists until the maturity of 

 the sporangium. (3) Andreace*, a single genus; 

 no operculuin ; the sporangium opens by 4-8 longi- 

 tudinal slits. (4) Sphagnacew, bog mosses; some 

 of the cells of the leaves grow larger than the rest, 

 lose their contents while their walls become spirally 

 thickened ; these cells open one into the other ; the 

 smaller cells are filled with chlorophyll, and form a 

 network round the large empty ones. The tissue 

 of the stem is in the centre a sort of pith ; outside 

 this a layer of long cells with thick walls ; outside 

 tliis an epidermal layer of large empty cells. The 

 male and female organs are either on separate 

 branches or separate plants. 



See articles LIVERWORTS, FERNS, GENERATIONS ( AL- 

 TERNATION or ). Also Kuskin, Proterpina ; Goebel, Out- 

 line* of Ctasrification and tptcial Morphology ( Oxford ) ; 

 Bennett and Murray, Handbook of Criiptoijamic Botany; 

 and works on British mosses by Stark, Holmes and 

 Gray. Bagnall, and Holikirk. The so-called Irish moss 

 (see CARRAGEEN) is a seaweed. Coreican moss and 

 Ceylon moss are names of algae (of the genus Plocaria) 

 used for producing an edible mucilage. Iceland Moss 

 (q.v. ) is a lichen. 



Mostagnncm, a town of Algeria, on the coast, 

 45 miles NE. of Oran, manufactures pottery and 

 has corn-mills and tanneries. Pop. ( 1886 ) 12,395, 

 more than one-third l>eing Europeans. It was a 

 place~pf 40,000 inhabitants in the 16th century ; 

 and has again grown up from its decayed state 

 since the French took possession in 1833. 



