THE BLACK MAIDENHAIR SPLEEN" WORT. 



a very lino example before us, tlic leafy part is eight inches long and seven broad, the stipes nine inches 

 long. They are quite smooth, and in outline are sometimes deltoid, or perhaps more correctly 

 pentangular, the apices of the lowest posterior pinnules forming additional angles ; sometimes ovate 

 with the point much attenuated. Full-sized examples of the latter, and a rather small frond of 

 the former state, are shown in our Plate. The smaller might he supposed to indicate a less mature 

 condition of the plant, but wo are scarcely prepared to adopt this explanation, on account of the 

 occurrence of equally small fronds in which the pentangular outlino is preserved, while again the 

 ovate fronds arc often abundantly fertile ; and we would rather suggest that it is an instance of that 

 profusion of form in Nature which mocks at our specific definitions. In the larger fronds, which an) 

 almost quadripimmtc, the pinme, especially the lowest which is also the largest* are of the same 

 subdeltoid outline as the frond iteclf, excepting that as the pinnules arc alternate and not opposite as 

 the lower pair of pinna) arc, there is a degree of obliquity almost producing a tm]wziform outlino. 

 The apices of the pinme, as well as of the frond, and generally of the pinnules, are caudate, with a few 

 sharp deep distant teeth. The larger pinnules of the lowest pinna) aro somewhat obliquely ovate- 

 attenuate, and thcii^livisions, tho secondary pinnules, are lanceolate, deeply pmnatiiid at a very acute 

 angle into linear lobes, the lower of which arc nlKmt three-toothed, the upper bifid at their points, 

 these lobes as well as the simple teeth at the apex of the pinnule itself being narrow and very acute. 

 The pinme towards tho apex of the frond, and the pinnules towards the apices of the pinme, become 

 gradually narrower than the Iwisal ones described above, until they both become reduced to linear- 

 lanceolate sharply toothed lobes, and these gradually merge into the simple linear teeth of the 

 caudate extremities. A similar mode of division, but on a smaller scale, obtains in tho smaller forms, 

 the fronds being only tripinnate, and the secondary pinnules narrower, and less deeply lobed. The 

 veins, though slender, aro very distinct ; they consist of a series of furcations, that is to say, the vein 

 which represents the midvein of the pinnules forks below each of the lobes or teeth, and the venule thus 

 produced proceeds along tho tooth or lobe until it nearly reaches the apex, being in tho case of the 

 former simple, ami in tho case of the latter again forked once or twice, according as there may be two or 

 three apical teeth. No one who has observed the venation in this plant, and is acquainted with our 

 British Asjtlcitwe. can fail to notice the similarity in form and division and in the condition of the 

 veins that exists between some of the pinnules of this plant, especially the shorter and broader ones of 

 the less divided fronds, and some fronds of A. scptcntrionalc. There is no definite midvein, but a series 

 of furcations only, so that this plant alone furnishes sullicient evidence against tho adoption of 

 Mr. Newman's group Am&rium as a genus. The son are very narrow, linear, borne, as in A. Adianttm- 

 nifftnm, contiguous to each other, and near the centre of the pinnules, Tho indusium is white, semi- 

 transparent, and entire. The plant is one of unusual elegance, both on accouut of its minute sub- 

 division, and its smooth shining surface. 



Some other variations of this species deserving of record, are included in the following summary : — 

 1- obtuwm (Willd,). This form, already descril>ed, is rarely more than bipiunate, though sometimes 

 tripinnate, with roundish or bluntly ovate pinnules, not very conspicuously toothed. It is less defined 

 than some other forms, some of the smaller states of the common plant approaching it very closely, but 

 as it occurs under different phases, it seems to claim recognition at least as a variety of secondary 

 importance, A tripinnate example of this form has been communicated by Mr, I). Moore, from the 

 county Antrim, Ireland. 



2, obfongum (BL). The chief peculiarity of this form is the parallelism of the sides of its fronds 

 which thus become narrow oblong, like what occurs in Lmtrm spinulosu ; the pinnae are short, 

 remarkably triangular, acuminate, the three lower pairs almost equal in size. The snlwlivisions are 

 small ; otherwise the structure is normal. We have received it from Mr, Jackson, of Guernsey, and it 

 has also liecn found by Dr. Allchin. 



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