26 



BRITISH MOSSES. 



question of interest, the relation between these stalked 

 heads and the inflorescence of the Moss. 



We have seen that Nature has been practising a piece 

 of severe economy in doing without the spore and the 

 whole machinery adapted for the production of spores and 

 substituting a gemma for a spore. We shall now see her 

 going a step further in the same course of economy and 

 doing without the gemma. She will produce protonema 

 from the existing Moss plant without the intervention of 

 spore or gemma. 



Fig. 15 represents a leaf of Orthotrichum Lyelli, a Moss 



Fia. 15. Leaf of Orthotrichum Lyelli, after Schimper. 



found both in the old and the new world, on the trunks 

 of trees : from this leaf, and especially from its midrib, are 

 seen growths of protonema, and these gradually change 

 into true roots, and on these roots buds are formed, which 

 buds develop into true Moss plants. At x will be seen 

 such a protonema divided into cells by transverse walls 

 further on the walls are oblique to the line of growth, and 

 the growth then assumes the form of a root and at y is 

 seen a bud destined to produce a Moss plant. 



