304 Mosses. 



Mosses. 



Mosses, Lindley observes, are among the smallest plants 

 with true leaves ; they are often so minute that the whole spe- 

 cimen, leaves, stem, fruit and all would escape the eye, if they 

 did not grow in patches ; and they never, even in the largest 

 kinds, exceed the height of a few inches. Nevertheless, they 

 are organized in a manner far from incomplete, with the ex- 

 ception of air vessels and breathing pores. They are usually 

 the first plants that show themselves on rocks, or walls, or 

 barren places, where no other vegetation can establish itself; 

 provided the air is damp they will flourish there, and in time 

 lay the foundation of a bed of vegetable mould, in which the 

 roots of grasses and otner stronger plants may find support, 

 till they in their turn have decayed and prepared the way for 

 shrubs and trees. This is the usual order observed by Nature, 

 in converting the face of rocks into vegetable mould, and 

 Mosses thus perform the office of pioneers to larger plants, an 

 office for which one would suppose their lilliputian size would 

 have hardly qualified them. They are formed precisely upon 

 the same plan as flowering plants, as far as the arrangement of 

 their organs of vegetation. They have in all cases a stem or 

 axis however minute, round which the leaves are arranged 

 with the utmost symmetry ; they have parts that answer to 

 seeds, enclosed in a case, and this case elevated on a stick, 

 which arises from among the leaves. But beyond this, analogy 

 ceases ; in all other points of structure, the Moss tribe is of the 

 most singular nature. They are said to be in fruit when the 

 stems are furnished with brown hollow cases, seated on a long 

 stalk. The theca wears a long cap not unlike that of the Nor- 

 man peasant women, with its high peak and long lappets, (see 

 plate,) this part is called a Calyptra ; when young, it was 

 rolled around the theca, so as completely to cover it like an 

 extinguisher, but when the stalk of the theca lengthens, the 

 calyptra is torn away from its support, and carried up upon 

 the tip. After a certain time the calyptra drops off; and then 

 the theca is in the best state for examination. It is terminated 



