EVOLUTIOX, II 



Is composed of marked types, just as is the animal 

 kingdom, and also that there are connecting links 

 between each class. The sea-weeds are joined by in- 

 termediate forms to the lichens, and the ferns and 

 club-mosses connect the flowerless with the flowering 

 plants. The whole plant world is bound together by 

 the evidence of a continued relationship from the 

 lowest to the highest form. 



The Unity of All Life. 



We have seen that the animal world may be con- 

 sidered a unit, a more or less closely connected as- 

 cending series of diverging organisms. Then we 

 have also seen that the plant world is linked together 

 in a manner that suggests progressive development 

 from its simplest to its most varied forms. But it is 

 found that animals and plants are joined by inter- 

 mediate forms that puzzle naturalists to tell which 

 kingdom they belong to. Haeckel calls these forms 

 Protista. They combine certain peculiarities of the 

 lowest forms of the two realms of life, and thus estab- 

 lish the unity of all life that exists upon the earth. 

 They represent a stage of existence, early in the 

 world's history, before life divided into the two 

 branches of animal and plant. Thus we find that 

 the quarter of a million of species of animals and 

 plants can be fairly assumed to have arisen from a 

 common origin. If they were created at once in all 

 these distinct forms, we are at a loss to see any mean- 



