IGi ON ANOMOCI.ADA. 



upper cell-layer, projecting over each as a conical papilla, but finally 

 ruptured when the contained antheridium is ready to burst and eject 

 its contents, as in Noferoclada. Compare also the male branches, or 

 amenta, of Anexira, where the antheridia are immersed in contip;uoiis 

 alveoles of the costa, and partially veiled by the incurved and toothed 

 pa<?ina — often almost cut into distinct leaves or bracts ; and the simi- 

 larly immersed, but usually more scattered antheridia of Pallavicinia, 

 where the pagina is narrowed, but otherwise unchanged, and a semi- 

 antical scale-like bract is set on over each alveole. 



In the prototypes of Blepharostoma and its allies the leaves have 

 been developed (in part) on a different plan, but I cannot delay to 

 adduce what evidence I possess on this head. Whether originally 

 generated at certain intervals along an axis or stem, by the addition of 

 cell to cell, by the usual process of cell-division, or differentiated out 

 of a previously-formed wing or border of the stem, I cannot doubt that 

 the lateral leaves have first come into existence in connection with 

 the male organs. This seems proved by the fact that throughout 

 the JungermannidecB, however much the stem-leaves may have become 

 metamorphosed, there is a constant tendency in the male bracts to 

 revert to the original type of a nearly equally 2-lobed transversal 

 leaf, whereof the antical lobe (to which the antheridia are axillary) is 

 incubous and the postical succubous.* 



• It is remarkable that a truly antical leaf — i.e., one placed at the very 

 middle of the upper side of the stem, symmetrical in outline and in its trans- 

 verse insertion— is exeeedingly rarein Hepatica^, though by no means uncommon 

 in Mosses. We have, however, an instance of its occasional presence in 

 Bazzania, where an antical leaf subtends each fork of the repeatedly dichoto- 

 mous stems. There is a near approach to an antical leaf in Lepidozia and some 

 other pinnately-branched genera, wher3 the leaf subtending each pinna, and 

 standing partly upon it, partly on the stem, is very nearly symmetrical, and is 

 less divided than the other stem-leaves. In the perianth an antical leaf seems 

 added on in a very few species of Lcjeunca and FrHllania. It is perhaps more often 

 present in the calyptra ; and from the capsule it is normally never absent, hence 

 its 4 valves, which are but modified leaves, as is beautifully seen in Jlerbcrta 

 (Scndtiicra), where each valve is deeply and unequally bifid, exactly as in the 

 etem-leaves. 



I reserve for another occasion the consideration of the modifications under- 

 gone by the leaves, until from having been united into a simple fi^it lamina they 

 have become in many genera very composite structures. It is singular that the 

 leaves bear traces in some genera of having been separated into two or three 

 distinct leaves in some prt;viou3 phase of the existence of the plant, and have 

 mostly (not always) become recotisolidated in part ((.e., connate) by very 

 obviims sutures, which sometimi's leave overlapping edges (e.n., in Scapania, 

 Schistochiln=Gi)ttschea,Microptert/fjiu)n, kc.) ■ while in the allied but more robust 

 and more highly specialised family of Mosses suc'h reunions are almost unknown 

 until we reach the peristome — that most beautiful and ondlesily- varied of any 

 organ in the whole vegetable kingdom, regard being had to the simple materials 

 out of which it is framed. Instances of the U'avos of Mosses becoming abnor- 

 mally connate are not, however, entirely wanting. I have seen, for instance, 

 the bracts of Pha^rum tnutieum united into an involucre which strongly recalled 

 that of Xardia Fimkii. 



As an exercise in the comparative anatomy of the Cryptogamia, I recommend 

 the student to compare SdagincVa among Lj'copods with Scnpanxa and Diplophyl- 

 ium among Uepatics, and with Rhacopiluiti, Iluo/crria Patrisicc, and a few other 

 Mosses which have tetrastichous leaves, those of tho two upper series being 

 smaller ; also the tristichous-leaved Hijpoptenjtjinni among Mosses, where the 

 third row of leaves is undermost and much the smallest, to many sti[)uliferous 



