67 a BRYACE^E. [Ackogexs. 



Mr. Heufrey thus states the case as regards the fructification of these plants :— 

 The anthcrids occur in the axils of the leaves or collected into a head, enclosed 

 by numerous variously-modified leaves, at the summit of the stem. They are pro- 

 duced either on the same heads as the pistillids, or in distinct heads on the same 

 individuals, such mosses being called monoecious; or the heads are found only on 

 distinct individuals, such mosses being termed dioecious. The structure of the 

 antherid is exceedingly simple : it consists of an elongate, cylindrical, or club-shaped 

 sac, the walls of which are composed of a single layer of cells, united to form a 

 delicate membrane. Within this sac are developed vast numbers of minute cellules, 

 completely filling it, and, the sac bursting at its apex at a certain period, these 

 vesicles are extruded. When the nearly perfect sacs are placed in water, the vesicles 

 within appear to absorb water, and swell so as to burst the sac of the antherid, and 

 often adhering together, they collectively appear to form masses larger than the 

 cavity from which they have emerged. Through the transparent walls may be seen 

 a delicate nlament with a thickened extremity, coiled up in the interior of each vesicle. 

 Often before the extrusion, but always shortly after, a movement of this filament is 

 to be observed when the object is viewed in water under the microscope. The 

 filament is seen to be wheeling round and round rapidly within the cellule, the 

 motion being rendered very evident by the distinctness of the thickened extremity 

 of the filament, which appears to be coursing round the walls of the cellule in 

 a circle. 



Tho pistillids of Mosses are the rudiments of the fruit or capsules. When young, 

 they appear as flask-shaped bodies with long necks, composed of a simple cellular 

 membrane. The long neck presents an open canal like a style, leading to the enlarged 

 cavity below, at the base of which, according to Valentine, is found a single cell 

 projecting free into the open space. This single cell is the germ of the future capsule; 

 at a certain period it becomes divided into two by a horizontal partition, the upper 

 one of these two again divides, and so on until the single cell is developed into a 

 cellular filament — the young seta ; the upper cells are subsequently developed into 

 the urn and its appendages, and as this rises, it carries away with it, as the calyptra, 

 the original membrane of the pistillid, which separates by a circumscissile fissure from 

 the lower part, the future vaginula. These observations of Valentine are not exactly 

 borne out by those of Schhnper in some of the details. According to this author, 

 the lower part of the pistillid (the germen of Brown) begins to swell at a certain 

 time, when a capsule is to be produced, becoming filled with a quantity of what he 

 terms " green granulations." As soon as the thickness has become about that of the 

 future seta, the cell-development in the horizontal direction ceases, and its activity 

 is directed chiefly to the upper part, which begins to elongate rapidly in the direction 

 of the main axis. This elongation causes a sudden tearing off at the base, or a little 

 above it, of the cell-membrane enveloping the young fruit, and the upper part is 

 carried onwards as the calyptra; the lower part, when any is left, remains as a little 

 tubular process surrounding the seta. While the young fruit is being raised up by 

 the growth of the seta, the portion of the receptacle upon which the pistillid is borne, 

 becomes developed into a kind of collar, and at length into a sheath (the vaginula) 

 surrounding the base of the seta which is articulated into it there. 



Bofmeister describes the details much in the same way as Valentine. He states 

 that there exists at the point where the "style "and "germen" of the pistillid join, 

 a cell, developed before the canal of the style has become opened. In those pistillids 

 which produce capsules this cell begins at a certain period to exhibit very active 

 increase ; it becomes rapidly divided and subdivided by alternately directed oblique 

 partitions into a somewhat spindle shaped body formed of a row of large cells. Mean- 

 while the cells at the base of the germen are also rapidly multiplied, and the lower 

 pari ut the pistillid is greatly increased in size. The spindle-shaped body continues 

 to increase in length by the subdivision of its uppermost cell by oblique transverse 

 walls, and the opposition which is offered by the upper concave surface of the cavity 

 of the germen, causes the lower conical extremity of the spindle-shaped body to 

 penetrate into the mass of cellular tissue at the base of the germen, a process which 

 resembles the penetration of the embryo into the endosperm in the embryo-sac of 

 certain Howering plants. The base of the spindle-shaped body, which is in fact the 

 rudiment ol the fruit, at length reaches the base of the pistillid, and penetrates even 

 some distance into the tissue of the stem upon which this is seated. The growth of 

 ,'"' upper part going on unceasingly, the walls of the germen are torn by a circular 

 nstureandthe upper half is carried upwards, bearing the calyptra, the lower part 

 torming the faginule. The upper cell of the spindle-shaped body then becomes 



.?,' IV'"' 1 " 1, " tl "' capsule, and the calyptra often becoming organically connected 

 men this, as the base of the seta does with the end of the stem; it, in such cases, 



