242 LUTHER BURBANK 



low order of development, showing relatively 

 little diversity of form and small capacity for 

 adaptation. 



The most conspicuous of them with which the 

 ordinary observer is familiar, namely, the ferns 

 bear a striking resemblance in contour to plants 

 of the remote Carboniferous Era, traces of which 

 have been preserved in the coal beds. And there 

 can be no doubt that this persistence of the 

 primitive form has been largely due to the special 

 method of fertilization which the ferns have 

 retained. 



If it be permitted to carry personification one 

 stage farther, we might say that the ancestors 

 of the ferns belonged to a conservative family, 

 jealous of its independence, and unwilling to 

 enter into outside alliances. 



And the penalty of conservatism here, as so 

 often in the range of human experience, has been 

 racial stasis. 



PLANTS THAT HAVE LEFT THE UNION 



It would appear, however, that there are 

 certain races of plants that were once members 

 of the plant-insect alliance but which are now no 

 longer in the union. 



These apostates include two quite different 

 tribes of plants. 



