174 SECOND GROUP. MUSCINEAE. 



Gemmae, which, like those of the Marchantieae, are stalked cellular bodies pointed 

 at both ends or lenticular in shape, occur in Aulacomnion androgynum 1 on the summit 

 of a leafless prolongation of the leafy stem (fseudopodium), and in Teir aphis pellucida 

 enclosed in a delicate cup formed of several leaves, out of which they afterwards 

 fall (Fig. 125, 126). Some species of Bryum have gemmae in the axils of the 

 leaves; Conomitrium juliamtm and Cinclidotus aqtiaticus are multiplied, according 

 to Schimper, by leafy branches which become detached from the stems. 



The sexual organs of the Mosses are usually to be found in numbers at 

 the extremity of a leafy axis, inclosed in an envelope of leaves often of peculiar 

 form, and mixed with paraphyses. Such an assemblage of organs terminates the 

 growth of a primary axis (Acrocarpous Mosses) or it appears at the extremity of 

 an axis of the second or third order (Pleurocarpous Mosses), in which case the 

 growth of the primary axis is unlimited. Antheridia and archegonia may be found 

 together in the same group, and then the arrangement is bisexttal, or one kind 

 only constitutes the group, and in that case the plant which bears them is either 

 monoecious or dioecious; the male organs are sometimes on smaller plants of shorter 

 duration, as in Funaria hygrometrica, Dicranum undulatum, and others. Groups 

 which contain both organs, and those with female organs only, resemble one another 

 in outward appearance, while the male groups have a habit of their own. When 

 antheridia and archegonia are both present in the same group, they stand either side 

 by side on the top of the stem in the centre of the envelope (perichaetium), or apart 

 from one another in two groups or separated by special leaves of the envelope ; 

 in the latter case the antheridia are arranged in a spiral line in the axils of the 

 leaves round the group of archegonia in the centre. The envelope in the female 

 and mixed groups is in the form of an elongated and all but closed bud, formed 

 by several turns of the leaf-spirals ; the leaves are like the foliage-leaves and 

 smaller towards the centre, but grow all the more vigorously after fertilisation. 

 The male envelope (perigoniuni) is formed of broader stouter leaves and has 

 three forms; like the female it usually has the form of a bud, but is shorter and 

 thicker, with the leaves often of a red colour and diminishing in size towards the 

 outside; these groups are always lateral. Those on the other hand which take the 

 form of small heads are always terminal on a stouter shoot, and are globular in 

 form with leaves broad and sheathing at the base, thinner and recurved above, 

 growing smaller towards the inside and leaving an open space in the centre of 

 the envelope for the antheridia ; they are sometimes also borne on a naked stalk, 

 a prolongation of the stem, as in Splachnum and Tayloria. Lastly, in the male disk- 

 shaped clusters the leaves of the envelope are quite unlike the foliage-leaves, being 

 broader and shorter, horizontally expanded above, delicate and of a pale green, 

 orange or purple colour, and always smaller as they approach the centre ; the 

 antheridia are in their axils (Mnium, Polytrichitm, Pogonatum, Dawsonia). The 

 paraphyses stand between or beside the sexual organs ; in the female inflorescences 

 they are always articulated filaments, in the male either filamentous or spathulate 

 and composed at the upper end of several rows of cells. 



The antheridium when fully formed is a stalked sac with a wall of one layer 



1 [Bower, Note on the gemmae of Aulacomnion palustre, Schwaegr. (Journ. Linn. Soc. 1884).] 



