THE EVOLUTION OF PLANTS 

 By C. Stuart Gager 



Director of the Brooklyn Botanic Garden 



In the conservatories of tl:^e Brooklyn Botanic Garden 

 there is an exhibit designed to give a bird's-eye view of the 

 plant kingdom/ The specimens are arranged on a bench in 

 the form of a tree, v^ith a trunk and lateral branches (Fig. l) . 

 The trunk represents the main course of plant life through 

 the ages; the branches are the great groups of plants. The 

 plants now living on the earth are to be thought of as 

 representing the tips of the branches of the genealogical 

 tree. 



Near the base of the trunk, on the lowest branch, are speci- 

 mens of some of the simplest plants known. As we pass 

 from these toward the other end of the bench we find plants 

 of gradually increasing complexity, until we come to the 

 orchids and composites at the topmost twigs. 



Along the trunk of this family tree is a label indicating 

 the changes met in a series of plants arranged in this order. 

 The points where the branches leave the main trunk are 

 "mile posts" calling attention to definite changes there repre- 

 sented. This long label is here reproduced, with the "mile- 

 posts" in heavy-faced type. The names of the great groups 

 of plants are in large and small capital letters: 



^ The exhibit here described was planned and installed by Dr. Alfred 

 Gundersen, Curator of Plants, Brooklyn Botanic Garden. 



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