314 



beyond the involute contracted segments of the frond which bears them. 

 What are called the thecae in Ophioglosseoe are improperly so termed, and 

 are much more analogous to the involucrum of Marsiiea, 



Geography. The earliest Flora of the globe, that indicated by the 

 fossil remains in the coal measures, was composed of Ferns, almost to the 

 exclusion of other plants ; and even in these islands, where the tribe now 

 forms an inconspicuous feature in the vegetation, grasses; herbs, and trees., 

 were represented by herbaceous and arborescent Ferns, and Fern-lilce plants. 

 An approach to this enormous disproportion between Ferns and the rest of 

 the Flora is even now exhibited in certain tropical islands, such as Jamaica, 

 where they are l-9th of the Phaenogamous plants ; New Guinea, where 

 D'Urville- found them as 2.8 to 122; New Ireland, where they were as 13 

 to 60 ; and in the Sandwich Islands, where they were as 40 to 160 ; and it is 

 clear, from the collections of Dr. Wallich, that Ferns must form a most 

 important feature in tlie Indian Archipelago. Upon continents, however, 

 they are far less numerous : thus, in equinoctial America Humboldt does not 

 estimate them higher than I -36th ; and in New Holland Mr. Brown finds 

 (hem ]-37th. They decrease in proportion towards either pole: so that 

 in France they are only l-63d; in Portugal, 1-1 16th; in the Greek Ar- 

 chipelago, l-227th; and in Egypt, l-971st. Northwards of these coun- 

 tries their proportion again augments, so that they form 1-3 1st of the 

 Phaenogamous vegetation of Scotland ; l-35th in Sweden; l-18th in Ice- 

 land; 1-lOth in Greenland; and l-7th at North Cape. (See a very good 

 paper" upon this subject by D'Urville, in the Ann. des Sc. Nat. 6.51.; also 

 Brown's Appendix to the Congo Voyage, 461.) Mr. Brown has observed 

 (Flinders, 584), that it is remarkable, that although arborescent Ferns are 

 found at the southern extremity of Van Diemen's Island, and even at Dusky 

 Bay in New Zealand, in nearly 46° south latitude, yet they have in no case 

 been found beyond the northern tropic. 



■ Properties. The leaves generally contain a thick astringent mucilage, 

 with a little aroma, on which account many are considered pectoral and 

 lenitive, especially Adiantum pedatum and Capillus Veneris ; but almost any 

 others may be substituted for them. Capillaire is so called from being prepared 

 from the Adiantum Capillus Veneris, a plant which is considered to be un- 

 doubtedly pectoral and slightly astringent ; though its decoction, if strong, 

 is, according to Dr. Ainslie, a certaiit emetic. The Peruvian Polypodium 

 Calaguala, Acrostichum Huacsaro, and Polypodium crassifolium, are said to 

 be possessed of important medicinal properties, especially the former ; their 

 effects are reported to be solvent, deobstruent, sudorific, and antirheumatic ; 

 antivenereal and febrifugal virtues are also ascribed to them. See the Pharma- 

 copceia Madritensis, 1792, and hamhcri'i Illustration of the Genus Cinchona, 

 1 14. The leaves of Adiantum melanocaulon are believed to be tonic in India. 

 Ainslie, 2. 215.- The tubes of the pipes of the Brazilian negroes are manu- 

 factured from the stalk of Mertensia dichotoma, which they call Samanbaya. 

 Pr. Max. Trav. 96. The bruised fronds of the fragrant Angiopteris evecta 

 are employed in the Sandwich Islands to perfume the Cocoa-nut oil. Poly- 

 podium phymatodes is also used for the same purposes. D'Urv. The 

 stem is, on the contrary, both bitter and astringent ; whence that of many 

 species, such as Aspidium Pilix Mas, and Pteris aquilina, has been em- 

 ployed as an anthelmintic. Thtyhave also been given as emmenagogues 

 and purgatives. Osmunda regalis has been employed successfully, in doses 

 of 3 drachms, in the rickets. The rhizoma of Aspidium Filix Mas has been 

 analysed, and found by M. Morin to contain, '1st, volatile oil; 2d, a fat 

 matter composed of claine and stearinc ; 3d, gallic and acetic acids ; 4th, 

 uncrystallisable sugar; 5th, tannin; 6th, soap; 7th, a gelatinous matter 



