CHAPTER X 
THE ALGA 
Puants that have the simplest bodies and those that 
grow and form new individuals like themselves in the sim- 
plest ways are found in a large group known as Thallo- 
phytes. There are no roots and leaves in this group, as in 
the larger plants with which we are more familiar, but bod- 
ies that are globular, or thread-like, or stem-like, with this 
stem often greatly branched. Many of these plants consist 
of single isolated cells and are extremely small—some so 
small that in order to study them in the best way they must 
be more or less magnified. Some members of the group are 
of enormous length, although in structure they are not com- 
plex. The entire group of Thallophytes is divided into two 
smaller groups,.the Alge and Fungi, the basis of division 
being the fact that the Alge contain a green coloring sub- 
stance and the Fungi do not. Familiar representatives of 
the Fungi are the toadstools and mushrooms. 
Alge are found in almost all regions where there is fresh 
water, also along the coasts and frequently out at sea in salt 
water, and a few are found out of the water. In the first 
lesson some general information should be obtained regard- 
ing the localities in which Alge grow and their general 
appearance. 
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