FERNS. 



49 



the oosphere, and the new plant is formed. This 

 draws its nourishment in the first instance from the 

 prothalUum ; hut the latter presently disappears, and 

 the young fern hegins to put out independent roots. 



Geographical Distribution. — Ferns 

 require shade and a damp atmosphere. 

 They are most ahundant in tropical 

 America, where they reach their 

 maximum concentration " amongst the 

 dripping rooks of the higher level of the 

 Andes, the forests of their slopes and 

 xavines, and the dense humid flats that 

 horder the innumerable branches of 

 the Amazon, where the sun's rays and 

 the wind never penetrate the recesses 

 of the primeval jungles, and climbers 

 and parasites contest with the leaves 

 of bright flowering trees for the posses- 

 sion of the branches." Mr, Baker, 

 from whose paper on the subject we 

 ■quote the foregoing passage, sum- 

 marised the distribution of ferns thus : 

 — Tropical America, 950 species (42 per 

 ■cent, of all known ferns, three out of 

 four not being found elsewhere) ; 



sally admired for the graceful lightness of their 

 delicate green fronds, which the dark stalks throw 

 into greater prominence ; and so invaluable to the 

 gardener from the profusion with which these fronds 

 are produced. Perhaps no ferns are so 

 much used with out flowers as the 

 Maidenhairs. Extending widely, as 

 they do, over the tropical and tempe- 

 rate regions of both hemispheres, they 

 find their headquarters in tropical 

 Ainerica. About a hundred species of 

 A.diantmn are known, and a. large 

 number are in cultivation. Of the 

 species requiring stove treatment, one 

 of the most peculiar, although perhaps 

 not of the most beautiful, is A. reni- 

 forme, a native of Madeira and Tene- 

 ri£Ee. This is distinguished at a glance 

 by its simple roundly kidney-shaped 

 Ironds, about two inches across, having 



the sori situated all round the edge ; 

 Pig. 1.— ProtliaUium of Maiden- ., , j. jj. j jl_ js j. • 



hair, seeo from below, witli the stems are tufted, from four to six 

 youag fern attached. j)p, inches high. A variety, known as 

 the prothalhum (magnified .^,. „ iX ~,r 



about thirty times) j d, the asanfohum, comes from the Mauritius ; 

 young fern; ww, its first y^-j^g ^n allied species, A. Farishii, is 

 and second roots; 7i, root- . „ ■.r ■, • ■, i, •,, , 



hairs of prothallium. a native of Moulmem and the Malaj- 



Peninsula : these form a little section 



tropical Asia and Polynesia, 863 



species, 427 being ^..^Emj-^ °* ^^^ genus very 



peculiar; Polynesia, ' ^V ■^'^^^^n'ls^ distinct from the re- 



380 species, 150 \ ' ^ >>. maining species. A. 



peculiar ; tropical W y/ \ ''.'■T- trapeziforme is a well 



Africa and islands, ' ' ■ifv. ' , , "\ known, handsome 



346 species, 127 l' J ' V 4 plant, of wide distri- 



peouhar ; south tem- . J - i.-" '"' - . ' ^ _^ bution from Mexico 



perate America, 118 \ ,"..■*' .. ' "' '*?' * ^^'•'* C " W to Brazil. It grows 



species, 32 peculiar ; ^,j' ^-,' ' "t./^ ' ^^^"^- ' '-^ ^°°^ ^"^ inches to 



temperate South '^ '■ ■* '" .^.■J^^s' "f '^^ ^ ^°"^ ^^^^' "^*^ 



America, 153 species, ^X^ ^r. '^ii^^"^' ^'^W/''^% stout, erect, shining, 



21 peculiar; tem- &^ \ . $Kv yA* * ^'^^^/if^^m ^^^ stems, and a 



perate North Ame- ^\^ \^ '*'M^'^y#f\S'V^^ llfracl '^^'^^ ^^^ spreading 



lica, 114 species, 37 ^^k \^ \ ^MMMfit'Ww^ nRMll P™°*' "^^^ich are 



pe(inliar; temperate ^^^ ^ /^^^MMftwl^^ /FTirl 7 trapeziform in shape, 



published some years * fl^^ 5^^W WlwH^il "iSi^^^^W- '^""'^'^ ^^^^ ^^"^^ 



approximately cor- "^ ^ ' MW \ H^^=-=i^, ^„,„ j^g^g ^^^ ^^.^ 



lect, considerable Fjg. 2.— l, prothallium of Male Fern (natural size); 2, the same, much ^'^°'''" stems, and 



■additions bavins' enlarged; 3, autheridium before bursting; 4, antheroidcens escaping slender pinnate 



? from antheridium ; 5, antheroid cell ; 6, antherozoid or spermatozoid ; . n j! +1, • + 



however, been made 7 archegonium (all much enlarged). tronas ot tnm tex- 



to the Madagascar 



iem-flora especially during even that short period. 



Maidenhair Perns (Adiantum). — Few genera 

 ■of ferns are more popular than this, including as it 

 does the various forms of Maidenhair; so univer- 



ture, a foot, or often 

 less, in length. These are frequently elongated at 

 the apex, and take root, as is also the case with 

 the allied A. caitdatum, which is very much like 

 A. lunulatum, but of a leathery texture. A. lunu- 

 latum is widely diffused in both the Old and 



