EUROPE AND NORTH AMERICA. 21 
we view them in profile, and also to the central aggregation of the 
contents of the organ. The antheridium bursts at the apex, the 
margins of the aperture rolling back, and a cloud of lenticular 
vesicles escapes, each of which contains a spirally coiled an- 
therozoid. The antherozoids are soon set free, and glide about 
with great activity ; their form is that of a fine thread of 23 coils, 
clavately thickened at one end, and at the opposite attenuated 
extremity provided with two long, extremely fine vibratile lashes. 
Surrounding the antheridia are exceedingly fine web-like 
paraphyses, which differ widely from those of mosses in being 
branched and twisted ; they arise from the cuticular layer of the 
branch, and no doubt convey moisture to sustain the vitality of 
the antheridium, but they disappear as soon as fertilization of 
the archegonium is completed. 
The bracts or covering leaves of the male inflorescence resemble 
the ordinary branch leaves in structure, but are shorter and more 
closely imbricated, and also often richly coloured, being purple in 
S. acutifolium, fulvous in S. cymbifolium, ochraceous in S. zner- 
medium, Sc. 
THe ARCHEGONIUM. 
The female inflorescence appears on a short lateral branch at 
the side of the capitulum, and at first takes the form of a long, 
attenuated, deep green bud of sheathing perigynial leaves, the 
innermost of which are the longest. Within these, and surrounded 
by the rudimentary perichetial bracts, are one to four archegonia, 
resembling those of true mosses, but having fine branched para- 
physes like those of the male inflorescence. They have shorter 
pedicels, and consist of an oblong ventral part which elongates 
upward into a cylindric neck or stylzdium, formed of six rows of 
cells. 
The first formation of the archegonia and progress of their 
development are fully described in the respective treatises of 
Hofmeister and Schimper. When arrived at maturity the apex of 
the archegone swells up and bursts, and the margins roll back, 
leaving a trumpet-shaped orifice; this aperture extends down- 
ward as a fine tube to the cavity of the archegonium, and forms 
the channel down which the antherozoids pass to fertilize the 
central cell. 
M. Roze observed the mode of impregnation of the archegone 
by placing some mature but still closed ones in water on a slide, 
