260 



Mosses to be Found in May. 



at first filled with, a semi-gelatinous loosely cellular tissue, each 

 cellule containing a sperniatozoid, which consists of a spiral 

 fibre, having attached to it a very small oval or roundish cor- 

 puscle, which is usually found near the middle of the spire. On 

 the escape of the contents of these antheridia when mature, 

 more or less of an explosive action takes place, and very soon 

 after being launched into the water the spermatozoids begin to 

 fidget, then to gyrate rapidly within the cells, and eventually 

 bursting the walls of their cellules, they escape from confine- 

 ment, and may be seen for several hours moving about in 

 various directions in the water, as if wild with new-born joy at 

 their escape from imprisonment. 



Thus far we have treated of the barren flower only, but the 

 genus being monoicous, the fertile flower may easily be found ' 

 by dissection at the apex of a young shoot at precisely the same 

 season, and on the same individual plant. This flower is com- 

 posed of slender flask-shaped bodies, called archegonia, which 

 are mixed with jointed filaments named paraphyses, and both 

 surrounded by a little cluster of leaves, which stand erect, and 

 which at length become the perichcetium. 



In length the archegonia somewhat exceed the antheridia, 

 but they are much more slender, indeed filiform, except towards 

 the base, where they appear slightly tumid, and at the apex, 

 which is somewhat expanded, the filiform connection between 

 the apex and the base being a canal in which is lodged a 

 roundish vesicle, the nucleus or germ of the future capsule and its 

 fruit-stalk ; and the perfect archegonium soon becomes enlarged 

 and swells out by the increase in bulk 

 of the vesicle within it, which at length 

 rends it asunder by a horizontal fissure 

 near its base. The upper part is then 

 converted into the calyptra, and the 

 lower becomes the vaginula, while the 

 rudimentary vesicle itself is metamor- 

 phosed into a fruit-stalk, its tapering 

 base inserted firmly into the vaginula, 

 and having its apex sheathed by the 

 embryo calyptra. This stalk or seta 

 goes on increasing in length until it has 

 attained its full height, until which time 

 tho apex remains, as it were, stationary, 

 but then it swells out, and developes 

 into the capsulo. This capsule consists 

 of a central pillar, or column, called the 

 columella, surrounded by a membranous 

 pouch or bag, called the sporular sac or 

 membrane, within which the spores, analogous to the particles of 



