CHAPTER V 
THE FUNGI 
ALL of the plants considered hitherto, except the 
bacteria, have been characterized by the presence of 
chlorophyll and the accompanying power of assimilat- 
ing carbon dioxide as food. While the latter property 
‘may be said to be characteristic of all typical plants, it 
must be remembered that there are very many plants, 
especially among the Thallophytes, where this power 
is wanting, and which are quite destitute of any trace 
of chlorophyll. It is usually supposed, although this 
is not universally admitted, that these plants are the 
descendants of green ancestors, and have lost their 
chlorophyll through the adoption of parasitic or sapro- 
phytic habits, ¢.e. feeding upon living or dead organic 
bodies from which they derive the carbon compounds 
necessary for their growth. All of these chlorophylless 
plants below the mosses are known as Fungi, and con- 
stitute a sub-kingdom which may be considered to have 
been developed parallel with the Algz, or possibly 
may have been derived from them. The Fungiare very 
numerous, far exceeding the Algz in number of species. 
Most of them are probably plants of comparatively 
modern origin, as very many of them are dependent as 
parasites upon various flowering plants, often being con- 
fined to a single species as host,! and presumably have 
1 Host — the animal or plant upon which a parasite lives. 
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