2P6 HALF-HOURS IN THE GREEN LANES. 



accumulates so as to form a good part of our peat or 

 turf deposits. The latter species grows in water, 

 and may perhaps be found in such a tarn or pond as 

 that whose chief contents we have already described. 

 Should the student wish to become a bryologist, 

 he will have to use the microscope very assiduously. 

 Only by this means can he thoroughly understand the 

 structural beauty of mosses. But he will find his 

 labours more than recompensed 

 in the many interesting details 

 brought to light. Let us glance 

 at a few of these. In Fig. 222 is 

 given the spore of the Rope-Moss 

 (Fimaria liygrometrica) one of 

 the commonest mosses growing on 

 waste ground, garden paths, &c., 

 , and which is remarkable for its 



rseudopodium of Aula- 



androgy- sensitiveness to moisture, the stem 

 twisting in a very lively fashion 

 when a shower of rain falls after 

 some long continued drought. These spores are 

 less than the thousandth part of an inch in 

 diameter. You see them sprouting in Fig. 223, 

 and in Fig. 224 you observe how cell has been 

 added to cell, and the filament elongated so as to 

 produce tlio green films you see, in spring, cover- 

 ing damp walls and banks. This is called the 

 prothallium, and it is from it that the young moss- 

 plant will bud, after which it dies away. In some 

 mosses a portion of the leaves are altered into 



