FUNGUSES _ 67 
much a flavour of death to be pleasant. The rotting 
twig is beautified by the grey pendants of the “Old 
Man’s Beard,” as it is sometimes called, and near by, 
perhaps, the mouldering earth may be adorned with the 
green branches and the crimson cups of the Cladonias. 
In this group are included the litmus family, which is 
of the highest importance to chemists. From it is pre- 
pared litmus paper, which has the extraordinary power 
of changing colour in presence of certain chemical 
qualities. It may be either blue or red, but if you hold 
a blue paper over a fuming acid, e.g. hydrochloric acid, 
the slip will promptly turn red before your eyes. Then 
hold it over the opposite of an acid, an alkali, such as 
ammonia, and it will immediately go blue again. If you 
happened to have a red paper originally you would see 
the process reversed. 
Other members of this group of some importance are 
the Iceland Moss, which is used for jellies, and the Rein- 
deer Moss, upon which the reindeer in Norway live in 
the winter, using their broad, shovel horns to clear away 
the snow. Of course neither of these can be called a 
true moss, for they are not yet in the proud possession of 
differentiated stem and leaves. The highest alge, as we 
saw, approached the stage, but could not fairly be said to 
have entered on it. We always have to remember that 
classes and groups shade into one another, and the best 
man in the second eleven is usually just about as good 
as the worst man in the first. | 
So we leave our alge and fungi, and pass respectfully 
to the Mosses, 
