Lycopodales.] MARSILEACE^. 73 



Delile has published an account of the germination of Isoetes setacea, from which it 

 appears that its sporules sprout upwards and downwards, forming an intermediate soUd 

 body, which ultimately becomes the stem, or corm ; but it is not stated whether the points 

 from which the ascending and descending axes take their rise are uniform. In Pilulai-ia 

 Mr, Valentine finds, that germination takes place invariably from a fixed point. Delile 

 points out the gi'eat affinity that exists between Isoetes and Lycopodium, particularly 

 m the relative position of the two kinds of reproductive matter. In Lycopodium, he says 

 the pulverulent spore-cases occupy the upper ends of the shoots, and the granular spore- 

 cases the lower parts : while, in Isoetes, the fonner are found in the centre, and the 

 latter at the cu-cumference. If this comparison is good, it will afford some e\-idence of 

 the identity of nature of these bodies, and that the pulverulent ones are at least not 

 anthers, as has been supposed ; for in Isoetes the pulverulent inner bodies have the 

 same organization, even to the presence of what has been called their stigma, as the 

 outer granular ones ; so that, if Isoetes has sexes, it will offer the singular fact of its 

 anther ha\ing a stigma. The anatomy of Isoetes is described by Mohl in the Linncea, 

 xiv. 181. 



The Pepperworts evidently approach the Clubmosses through Isoetes, which is some- 

 times referred to the one Order, sometimes to the other. Their genus AzoUa appears 

 to bring them into contact with Jungermanniacese. Accordmg to Mr. Ginffith, Marsilea 

 evidently appears to connect Sahdnia with Ferns ; " its important differences from Sal- 

 vinia consist in the capsules, which correspond to the secondary capsules of that family, 

 being developed withm the substance of a modified leaf, in theii' occui'ring mixed with 

 each other, and in the spores of the pedicellate capsules not becoming imbedded in 

 apparently cellular masses." 



AU are inhabitants of ditches or iumidated places. They do not appear to be aff"ected 

 by climate so much as by situation, wherefore they have been detected in various parts 

 of Em'ope, Asia, Africa, and America ; chiefly however in temperate latitudes. 



Uses imknown. 



Pilularia, Linn. 

 Marsilea, Linn. 



Lemna, Juss. 



Zaluzianshia, Neck. 



GENERA. 



Azolla, Lam. 



Carpanthus, Raf. 



Rhizosperma, Meyen. 

 Salvinia, Michel. 



Numbers. Gen. 5. Sp. 24. 



Isoetes, Linn. 

 Calamaria, Dill. 



Filices. 

 Position. — Lycopodiacese. — Marsileace^. — Jungerraanniaceae. 



with hairs ; tegument open at the top ; mature reproductive organs solitary, or in racemes of 3-5, about 

 the size of a pea, covered with brown rigid hairs. The upper ones of each raceme, (or lowest as regards 

 general situation,) contain innumerable sphaerical bodies, of a brownish colour and reticulated cellular 

 surface, terminating capillary simple filaments. These again contain a solid whitish opaque body. The 

 other, which occupies the lowest part of the raceme, and which is the first and often the only one deve- 

 loped, is more oblong, containing 6-18 larger, oblong-ovate bodies, on short stout compound stalks : 

 colour brown, surface also reticulated. Each contains a large, embossed, opaque, ovate, free body, of a 

 chalky aspect : it is three-lobed at the apex, and contains below this a ca\ity lined by a yellowish mem- 

 brane, filled with granular and xiscid matter and oily globules. 



Azolta pinnata.— The growing points present a number of minute confers'oid filaments, the assumed 

 male organs, which at certain periods may be seen passing into the foramen, the o\-ula becoming resolved 

 into their component cells within the cavity of that body ; organs of reproduction in pairs, attached to 

 the stem and branches, one above the other, concealed in a membranous involucrum ; o\'ula atropous, 

 oblong-ovate, with a conspicuous foramen and nucleus, around the base of which are cellular protu- 

 berances ; capsules of each pair either difform — in which case the lowest one is oblong-ovate, the upper 

 globose — or both of either kind, generally perhaps the globose, presenting at the apex the brown remains 

 of the foramen, and still enclosed in the involuci-um ; upper half generally tinged with red ; the oblong- 

 ovate capsule opens by circumcision ; with the apex separate the contents, which consist of a large yellow 

 sac contained in a fine membrane, the remains of the nucleus (or the secondary capsule.) The sac is 

 filled with oleaginous granular fluid, and surmounted by a mass of fibrous-tissue, by which it adheres 

 slightly to the cah^ptra ; on the surface of the fibrous tissue are 9 cellular lobes (the three upper the 

 largest), which when pulled away, separate with some of the fibrous tissue, and so appear pro>ided with 

 radicles. The globose capsule has a rugose surface from the pressure of the secondary capsules within ; 

 these are many in number, spherical, attached by long capilliform pedicels to a central much branched 

 receptacle ; each contains two or three cellular masses, presenting on their contiguous faces two or three 

 radiciform prolongations. In their substance may be seen imbedded numerous yellow grains, the spores. 



