X. SPHAGNA. 931 



phyll cells, with a pedicel formed of 4 series of cylindric cells. The antherozoids 

 escape by a rupture of the top of the antheridium (as in Hepaticw and Mosses), which 

 then quickly decays ; and this distinguishes it from the antheridia of Mosses, which 

 sometimes persist for years., Thuret has observed that the cells in the antheridia 

 are lenticular, flatter on one side than on the other, as in Hepaticce, whilst in Mosses 

 they are perfectly symmetrical ; each contains an antherozoid, which is set free by the 

 rapid dissolution of the cell-wall under water. The antherozoid is a 2-haired 

 filament, spirally coiled twice, adhering to a vesicle, which, according to Eoze, 

 contains an amylaceous granule. Schimper says that the antherozoid, as long as it 

 is enclosed in its cell, revolves rather quickly upon its axis; but, as the spiral tends 

 to become excentric, it soon leaves its prison, and once free it adds a movement of 

 progression to that of rotation ; the latter appears to be produced by the rapid 

 oscillation of the 2 filaments, which thus perform the function of vibrating hairs. 

 The spiral itself has no motion, either of contraction or dilatation, and the anthero- 

 zoid appears to be propelled upon the principle of the Archimedean screw, its oscil- 

 lating filaments causing it to revolve on its axis, and its helicoid form determining 

 its advance in the liquid ; the more rapid the rotations are, the quicker is its pro- 

 gression. The antheridia are accompanied by numerous paraphyses, which are 

 branched very fine succulent filaments, evidently adapted to retain moisture around 

 the antheridium, and to facilitate its dehiscence. 



The FEMALE INFLOEESCEITCE is an elongated bud, composed of variously formed 

 leaves tha.t form an involucre to the archegonia ; in the centre is a whorl of very 

 small leaves, constituting the perichcetium of the fruit. The archegonia, numbering 

 1-3 (rarely 4), occupy the rounded top of the fertile branchlet ; one alone ripens. 

 Their structure is nearly identical with that of Mosses and Hepaticoe. Like the 

 antheridia, they are accompanied by numerous filaments (parop^ses), much branched 

 and very flaccid, interlaced so as to resemble a loose arachnoid tissue. As soon as a 

 nucleus in the cavity of the archegonium is fertilized, as in Mosses, its cells rapidly 

 mi^ltiply, especially at the lower part ; soon it opens a passage across the foot of the 

 archegonium, perforates the top of the stem, and advances, continually multiplying, 

 to the place where the involucral leaves begin. This cellular tissue, once established 

 within the receptacle, that is to say, on that portion of the stem which is to form 

 the vaginula, develops so fast, that it becomes in a few days a hemisphere, or almost 

 a bulb, bearing the abortive archegonia on its sides. The dilated top of the stem 

 becomes the vaginula. A cushion is then developed in this protuberance, some- 

 times at the base even of the archegonium itself, which is the rudiment of the 

 future capsule. This enlarges without the smallest change occurring in the body of 

 the archegonium, which, in Mosses, at first enlarges simultaneously with the evolu- 

 tion of its contents. As the young fruit rises above the vaginula, its cellular layers 

 become modified ; the outer, which is to form the capsular walls, is still simple ; the 

 following layer, destined to form the sporangium, is equally simple ; the central cells, 

 which represent the commencement of the columella, are loose and transparent ; soon 

 the cells of the capsule and of the sporangium become doubled and quadrupled by 

 vertical division. The walls of the outer layer thicken and darken, and the sporangial 



So 2 



