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 i\ 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 beino- 

 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 

 6". acntifolium, fulvous in S. cymbifolium, ochraceous in .S. inter- 

 medium, &c. 



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 perichaetial 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 stylidium, 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. 



