ORGANS OF REPRODUCTION-. 367 



or six small leaves, of a very different appearance to them, 

 ie.Tmed perigonial, and constituting collectively a perigone. The 

 antheridia are regarded as the male organs, and the archegonia 

 as the female. 



The antheridia and archegonia sometimes occur in the same 

 perigone, in which case such Mosses have been termed her- 

 mafhrodite. More frequently, however, they are in different 

 perigones, and then both kinds of reproductive organs may 

 occiu' on the same plant, or on separate plants ; in the former 

 case we apply the term moncecious, in the latter dmcious {figs. 

 8 and 9). 



The antheridium is a somewhat elliptical, more or less rounded 

 or elongated cellular sac {fig. 802), which is filled at maturity 

 with a number of minute cells, c, termed sperm-cells ov zooihectB ; 

 in each of these there is a single spiral antherozoid, fhytozoon, 

 or spermatozoid. The antheridium opens by an irregular perfo- 

 ration at its apex, and thus discharges the sperm-cells with their 

 antherozoids. Among the antheridia there are generally to be 

 found slender cellular jointed threads {fig. 802,^), called ^ara- 

 physes, which are probably nothing more than abortive anthe- 

 ridia, as they appear to perform no special function. 



The archegonia, like the antheridia, are often surrounded by 

 filamentous cellular bodies, called parapJiyses, which appear to be 

 in this case abortive archegonia {fig. 803). The archegonmm is a 

 flask-shaped cellular body with a long neck, the whole somewhat 

 resembling an ovary with its style and stigma {fig. 803). The 

 neck is perforated by a canal which leads into a cavity, at the 

 bottom of which is a single cell, called the germ or embryonal- 

 cell. The case of the archegonium is called the epigone. This 

 germ-cell appears to be fertilized, as in Ferns, by the anthe- 

 rozoids passing down the canal until they reach it. In the 

 case of Mosses, however, the fertilized germ-cell does not di- 

 rectly develop a new plant like its parent, but after fertiliza- 

 tion has taken place, the germ-cell becomes gradually developed 

 into a somewhat conical body elevated on a stalk, and as it 

 grows upwards it bursts the epigone, and carries one portion of 

 it upwards as a kind of hood, while the other portion remains 

 below as a sort of sheath round the stalk. It will thus be seen 

 that what is commonly called the fructification of Mosses, — 

 namely, the sporangium {figs. 805 and 806, u), is not the real 

 fructification, but its product. The central portion formed by 

 the development of the embrj-onal cell, is called the sporangium 

 { ngs. 805 and 806, it, sp), the stalk the seta {fitgs. 804, t, and 

 805, p), the hood the calyptra {figs. 805 and 806, e), and the 

 sheath at the base, the vaginvXe {fig. 804, v). 



The sporangiv/m, when fully formed, is a hollow urn-like case 

 {figs. 806 and 807), the centre of which is usually occupied by 

 a cellular axis, called the columella {fig. 810), and the space be- 



