EVOLUTION OF PLANTS 
CHAPTER I 
INTRODUCTION 
Wiru the acceptance of the theory of evolution, the 
question of the origin and affinities of the manifold 
forms of life making up the organic world becomes of 
absorbing interest to the biologist, and the hope of 
solving some of these problems has been the great in- 
centive to much of the most brilliant work, both of 
zoologists and botanists, during the latter half of the 
nineteenth century. 
When we survey the vast assemblage of living organ- 
isms, the thought of arranging these in orderly sequence 
seems hopeless ; and indeed when we take into account 
how many forms must have disappeared and left no 
trace behind, it must be admitted that the task is one 
whose completion, if ever reached, must lie in the dis- 
tant future. Nevertheless the data are slowly but 
surely accumulating through the efforts of biologists 
whose patient researches are constantly adding to our 
knowledge, both by the discovery of new forms and 
by a more thorough examination of those already 
known. The constant improvement in the technical 
appliances for research, such as the microscope and 
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