FERN. 546 FERN. the latter being called sporophylls, as in the ostrich-fern [Struthiopteris) , the climbing fern (Lygodium), the royal tern [Osmunda), etc. An ordinary fern sporangium (spore-vessel) consists of a slender stalk bearing a spore-case. This case has a delicate wall formed of a single layer of cells, and extending vertically almost around it from the stalk, like a meridian about a globe, is a row of peculiar cells with thick walls, forming the heavy ring called the 'annulus.' The annulus is like a bent spring, and when the delicate por- tion of the case-wall yields the spring straightens violently, the case-wall is torn, and in the re- bound the spores are discharged with consider- able force. The true ferns are often divided into two great groups on the basis of the origin of their spo- rangia. In one case the sporangium is purely an external structure, being derived from a single epidermal cell, and such ferns are said to be 'leptosporangiate.' In other ferns the sporangium involves the deeper structures as well, and is really an internally developed organ; such ferns are 'eusporangiate.' The eusporangiate ferns are the more primitive forms, and probably were the only kind in the extensive fern display of the Carboniferous period. The leptosporangiate ferns are the modern and abundant forms. There are two great divisions of Filieales, namely the 'true ferns' (Filices) and the 'water ferns' (Hy- dropterida?) . Among the Filices six great families are ordinarily recognized, as follows: Osmun- daceae, containing the royal ferns; Gleicheniacea?, which are tropical forms; Schizaeacese, which in- clude the climbing ferns as well as various other peculiar genera: Hymenophyllacese, which con- tain the ferns with the most delicate bodies, often called the "filmy ferns'; Cyatheacea which in- clude among other forms the tree-ferns ; and finally Polypodiacese, the greatest and most high- ly organized family, to which almost all of the t rue ferns of the temperate region belong. The water-ferns ■ (Hydropteridse) contain but few forms, and grow either in water or marshy places. They are of particular interest from the morphological standpoint, because they are hetero- sporous if|.v. I. There are two distinct families. Marsiliaceae, represented by the common Marsilia, contain- semi-aquatic species with slender stems, which send down numerous roots into a mucky soil, and give rise to comparatively large leaves, each of which has a long erect petiole, and a blade- nf four wedge-shaped leaflets like a four- leaved clover. From near the base of the petiole another leaf-branch arises in which the blade is modified as a spore-bearing structure, which in- closes ill'- spore-case and becomes hard and nut- !: The other family is the Salviniacess, repre- sented i' Salvinia, whose species are floating Fossil Pebns. Leaves and stems of fossil ferns minim in all geological formation- above tin- Silurian, and they are especially abundanl in tin- Coal Measures of the Carboniferous a.L r c I ndeed tj i><' considered in hai e been I he of 1 in' Paleozoic land flora, not res -mi of t heir abundance, bui also be f their large Bize. Many of them were tree- in the a-t forests along the o) latei 1'ai' ozoic seas. large number of the r enera een i" have had ■ iii' i be i issue of i he fer- n - u i In modern adder's ' i ngue fern (Ophioglossum), and its allies the Marat- tias. Because of this structure, these genera are included in a suborder, the Eusporangia. Although fragmentary fern-leaves and some supposed stems are found in Lower Devonian rocks, well-preserved specimens are not found until the Upper Devonian (Catskill) sandstones are reached, where Archseopteris is obtained. In the Coal Measures, where ferns are abundant, the principal genera are Pecopteris, a tree-fern; Neu- ropteris, Archseopteris, Dictyopteris, Odontop- teris, Alethopteris, etc., which are herbaceous ferns of large size; and Hymenophyllum and Sphenopteris, which are delicate ferns that must have formed the undergrowth of the forest vege- tation. In the Permian and Triassic periods the most important genus was Glossopteris (q.v.) ; and an allied genus, Toeniopteris, is very com- mon in the Jurassic rocks. During Cretaceous time the ferns began to resemble more closely those of to-day, and in Tertiary time a large number of modern species appeared. Consult: Lyell, Geographical Handbook of AH the Known, Ferns (London, 1S69) ; Baker, Sum- mary of Sew Ferns Discovered Since 1874 (Lon- don. 1892) ; Hooker and Baker, Synopsis Filicum ( London, 1874 ) ; Eaton, The Ferns of North Amer- ica (Boston, 1880) ; Goebel, Outlines of Classifica- tion and Special Morphology of Plants, trans, by Garnsey (Oxford, 1887); Solms-Laubach. Fossil Botany (Oxford, 1891), contains a full bibliog- raphy of paleobotany, including works on ferns. Consult also: Zittel, Sehimper, and Barrois, Traite de paleontologie, Part II. Paleophytologie (Paris,1891) ; Bernard, Elements de paleontologie (Paris, 1895) ; Gardner, "Monograph of the Brit- ish Eocene Flora, Vol. I. Filices," Monographs of the Palceontographical Society (London, 1879- 82) ; Feistmantel and others, "Fossil Flora of the Gondwana System," Palceontologica Indica, Series II. and XII. (Calcutta, 1876-81). The most im- portant works describing the fossil ferns of North America are: Fontaine and White, "The Permian or Upper Carboniferous Flora of West Virginia and Pennsylvania," Second Geological Survey of Pennsylvania, vol. PP (Harrisburg, 1880) ; Les- quereux, "Description of the Coal Flora of the Carboniferous Formation in Pennsylvania and Throughout the United States." Second Geologi- cal Survey of Pennsylvania, Report of Progress P, vols. i.. ii„ and (Harrisburg, 1S80-84) : D. White, "Fossil Flora of the Lower Coal Measures of Missouri." Monographs of the United States Geological Survey, vol. xxxvii. (Washington, 1899). FERN, Fanny. The pseudonym of Mrs. Sara l'ayson Willis Parton. FERN, Male. A popular name given to the fern Aspidium fili.r-nias. or as some botanists call it, Dryopteris filisB mas. The male fern has a stout, more or less erect, chaffy, perennial root- Btoek, from which arise numerous annual, brighl green fronds, forming tufts one to four feel high. The slipe and midrib of i la- fronds are beset with brownish ehall'y scales. The frond is oblong lanceolate, acute al apes and narrow below: the pinna? arc lanceolate, somewhal scattered toward the base of the stalk, and often confluenl above; the fruiting bodies, or sori, arc borne near the midrib of the ultimate segments of the fronds. Male fern i- a native of Europe, -ia. North- em Africa ami (he New World, where it is found
