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The Naturalist. 



and worthy mission in seeking to propagate a love for natural 

 research, not because of any aid they may thereby give to the general 

 course of science, but because by teaching the people to investigate 

 the wonders of nature, to understand her perfect harmony, to 

 appreciate her exquisite beauty, and to get some glimpse into her 

 unfathomable mysteries, they may ennoble the individual and become 

 the benefactors of the community. 



ON MOSSES. 



By Wm. West. 



What is a moss ? No one but a student of mosses is able to answer 

 this question, for the great mass of people include under this designa- 

 tion small flowering plants such as the smaller species of saxifrage 

 and stonecrop, as well as some seaweeds, and also all (or nearly all) 

 the liverworts and lichens. I now mean to define what is meant 

 when a botanist speaks of a " moss," and in doing so I shall of 

 necessity touch upon the development and structure of this order of 

 plants. There is a group of plants termed Muscinece, which comprises 

 the hepaticae and mosses. The family of the hepaticse is the only one 

 likely to be seriously confounded with the mosses, and 1 must there- 

 fore endeavour to point out how we distinguish between the two 

 divisions of the group Muscinece. The group is distinguished by a 

 sharply defined alternation of generations. The spores of most of the 

 hepaticse develop a sexual generation, which is self-supporting, but 

 some of the hepaticse and all the mosses develop a protonema, which 

 may be termed a pro-embryo, and this produces a shoot giving rise 

 to the sexual generation. This protonema has a confervoid shape, 

 except in one or two instances where it is flattened. From this 

 generation there arises in the female sexual organ a new generation 

 caused by fertilisation — a very different structure, destined to produce 

 asexual spores — it is called the sporogonium by Sachs, but is usually 

 known as the sporangium, theca, capsule, or fruit. The sexual organs 

 are antheridia and archegonia. The mature antheridium (the male 

 organ) has either a longer or shorter stalk ; the outer layer of cells 

 forms a sac-like wall, enclosing a number of cells, from each of which 

 an antherozoid is formed. The antherozoids are freed by the apical 

 rupture of the antheridium ; they are spirally-coiled threads, thicker 

 at the posterior and tapering to a point at the anterior end, where 

 the two long cilia arise. The archegonium (the female organ) has a 



