CHAPTER III. 



ON THE DEVELOPMENT AND STRUCTUKE OF MOSSES. 



a. THE spores of Mosses, like those of most Fungi and of 

 many other Cryptogams, consist of a grumous mass contain- 

 ing occasionally minute oil-globules enclosed in a double mem- 

 brane, the inner one of which is hyaline and perfectly even, 

 and lines the outer one, which is more or less coloured and 

 often minutely sculptured. 



When the spores are sufficiently moistened, either on their 

 proper matrix or within the folds of compressed leaves, as in 

 Fissidens, and the temperature is favourable, the outer mem- 

 brane swells and ultimately bursts, giving egress to the inner 

 membrane, which soon protrudes and forms a little obtuse 

 tube. This elongates rapidly, and becomes septate and ulti- 

 mately branched, so as to form, together with the threads pro- 

 ceeding from other spores, a felt-like mass, which is often of 

 a bright green, and in this stage is often mistaken for some 

 species of Conferva. 



The joints are more or less filled with chlorophyll so long 

 as the threads are in a healthy state. The threads proceed- 

 ing from a single spore are capable of forming several fer- 

 tile buds, but whether in many cases more than one of these 

 comes to perfection depends upon the favourable or unfavour- 



