MOSSES. 



[ 514 ] 



MOSSES. 



where an inner circle occurs they are con- 

 tinuations of the spore-sac ; the outer wall 

 of the sporange is, as it were, continued by 

 the operculum. Ordinarily these do not 

 separate directly from each other when the 

 lid falls off, since one or several layers of 

 elastic cells, forming a ring (annulus, fig. 482) 

 round the mouth, split out from between 

 the sporange and its lid, and cause the latter 

 to fall off. 



The spores are developed in a distinct 

 epore-sac, which has one layer next the wall 

 of the capsule, and an inner layer next the 



Fig. 481. 



Fig. 482. 



Fig. 481. Kacomitrium fasciculare. Section of margin 

 of sporange, with a tooth of the peristome. 

 Mogn. 100 cliams. 



Fig. 482. Bryum ctespiticium, annulus. Magn. 100 diams. 



Fig. 483. Orthotrichum diaphanum. Portion of double 

 peristome, the outer composed of teeth, 

 the inner of cilia. Magn. 50 diams. 



Fig. 484. 



Neckera antipyretica. 

 Double peristome, the inner composed of teeth united 

 by cross bars, forming a trellis. 



Magnified 100 diameters. 



columella. The top of the columella ex- 

 pands into a kind of pseudo-operculum in 

 Polytrichum. In Phascaceae the columella 

 is absorbed. 



Allusion has been made to the sexual im- 

 port of the antheridia and archegonia. In 

 the reproduction of the Mosses the spores 

 produce a confervoid filament or protonema, 

 from the sides of which the young plants 

 with stem and leaves shoot ; and on these 

 the antheridia and archegonia are formed. 

 From the embryo-cell of the fertilized 

 archegonium arises the sporogonium, in 

 which the spores are formed. 



The Mosses exhibit a variety of forms of 

 vegetative multiplication. The lower part 

 of the stem often sends out horizontal 

 branches, which root and produce buds 

 (fig. 485), from which arise new leafy stems ; 



Fig. 486. 



Polytrichum undulatum. 



Creeping filaments with innovations. 



Magnified 5 diameters. 



and in this way, patches of moss frequently 

 increase to a great size. 



They also produce confervoid filaments, 

 which exhibit tuberous thickenings, a form 

 of gemma (figs. 488, 489), which may be 

 detached from each other like bulbils, so as 

 to propagate the plants without any sexual 

 reproductive organs. 



The protoplasm of these confervoid fila- 

 ments also forms Amoeboid bodies, and 

 gonidia or ciliated zoospores (Hicks). 



Gemma or minute cellular tubercles, 

 capable of development into new plants, 

 are likewise met with in other situations, 

 as in the axils of leaves, on the surface, the 

 margins (fig. 490), or at the tips (figs. 486, 

 487) of the leaves or the stems (fig. 491) : 

 these are formed of only a few cells at the 

 time they fall off, and illustrate well the 



