Leafy Mosses 



SPORE-CASE 



In the early stages of a developing spore-case the cells may 

 be distinguished as forming two groups, first an outer wall con- 

 sisting of a number of layers of cells and second an inner mass 

 of cells; the outer wall is separated from the inner mass by a 



Veil split up one side. 



Spore-case borne on a short 

 pedicel, lid wanting. 



Astomum Sullwantii. (See page 50). 



Spore-case with veil. 



space filled with air. The centre portion of the inner mass will 

 become the columella and the enclosing stratum of cells (arche- 

 sporium beginning of spores), will be the "mother-cells" of 

 the spores. Just outside the mother-cells between them and the 

 air-space will be a layer of cells (the endothecium). 



UJ ... 

 .tu.rt tilth. 



2Tbn t of ttUt 

 IfutUTt anx 



iVieH will** 

 Covt (listen 

 13. loVth tvatt* 

 a.nl f-r ic tkt. 

 Cdlt al>ov t to 

 form *UL. 



Funaria hygrometrica. Portion of 

 a vertical section through a young 

 sporogonium. 



Sphagnum acutifolium. Ehrh. Vertical 

 section through an early stage of a 

 sporogonium. 



THE LID OR OPERCULUM 



The upper part of the spore-case is in the leaf-bearing mosses 

 usually thrown off as a lid (operculum). In order that the upper 

 portion of the spore-case may be separated from the lower, either 



51 



