Carter XVI 
THE THALLOPHYTES 
The Thallophyta or thallophytes constitute Division I of the 
Vegetable Kingdom. As a group they represent the most 
simple and most primitive plants. Many of their living repre- 
sentatives like the bacteria, flagellates and slime molds possess 
characteristics of both plant ane animal so that they are believed 
to be near the first forms of life that existed on the earth. The 
greater number of the members of this division have bodies 
consisting of a thallus, a structure undifferentiated into roots, 
stems or leayes. Under the microscope the thallus shows neither 
tracheids nor tracheze. Some of the higher forms possess struc- 
tures superficially resembling and functioning like the roots, 
stems and leaves of higher groups. They reproduce asexually 
or asexually and sexually. 
They include the Schizophyta or fission plants represented by 
the bacteria and blue-green algae, the Flagellata or flagellates, the 
Myxomycetes or slime moulds, the Lygophycee represented by the 
diatoms, pend silks and desmids, the Chlorophycea or green alge, 
the Charophyta or stoneworts, the Phaeophycee or brown alge, the 
Rhodophyceae or red algae, the Hyphomycetes or fungi and the 
Lichens. 
The evolutionary or phylogenetic relationship of the above 
groups is so incompletely understood that the forms now to be 
considered will be discussed under the long established physio- 
logical groups of Algae, Fungi and Lichens. 
THE ALG 
The algze (sing. alga) are forms of thallophytes found on land 
and in fre kish or salt water. The lower forms consist for 
the most part of single cells or rows of single cells joined end to 
end to form filaments. The higher forms, however, possess 
structures which, while appearing like stems and leaves of higher 
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