HIDDEN MABRIAGES 



553 



FIG. 699. Corallina officinalis. 



n Seaweed whose steins and branches are thickly 

 coated with lime. (6) Tetraspores. 



produces its spores within the 



suckers through the cell-walls. 

 This mycele is perennial that is 

 to say, where the host is a per- 

 ennial plant. In each species there 

 is some particular part of the plant 

 where hyphse break through to pro- 

 duce their spores on the surface. 

 These spore-masses, usually black 

 or some dark colour that looks 

 black to the unassisted eye, have 

 caused the pests to be known as 

 " Smuts." Most people have seen 

 a field of corn with the ears all 

 " smutted," or covered with the 

 spores of Ustilago segetum. Tilietia 

 grains of Wheat, and causes the condition known to farmers as u bunt." 

 Urocystis violce disfigures the leaves of Violets, and lives perennially in the 

 rootstock. 



The Sphseropsidese are also minute Fungi. They produce perithecia like 

 the Pyrenomycetes, but these have no asci, the sporules or stylospores being 

 produced within the apex of hyphse. 

 The Hyphomycetese include the 

 well-known Mould Penicillium glau- 

 cum, and a large number of plant- 

 pests ; but many of them are sus- 

 pected of being not real species, but 

 temporary stages in the develop- 

 ment of some of the larger Fungi. 



The Class CHARACE.^, or Stone- 

 worts, consists of only two Orders, 

 Characese and Nitellese. They are 

 delicate fresh-water plants which 

 have a superficial similarity of form 

 to the Horsetails ; that is, there is 

 a main stem with whorls of leaves, 

 and branches of similar structure 

 to the main stems. The leaves 

 spring from distinct nodes, as in 

 the Equisetacese, and the branches 

 from the axils of some of the leaves, 

 where also are found the sexual 



organs. The entire internode i.e. 



,-, -, , , FIG. 700. A RED SEAWEED (Polysipnonw, 



the space between two nodes subulata). 



Consists Of One Very large Cell, in (a) Tetragonidium in two stages of growth. 



