EVOLUTION. 33 



fossils. The rocks have been subject to convulsions 

 and heat, which, in many cases, would destroy \k ^.ir 

 records. It is to be remembered also that the varia- 

 tion of species is usually a very slow process. We 

 have been accustomed to consider that all changes 

 have occurred within six thousand years, but when 

 we extend nature's operations to millions of years, it 

 is not so surprising that the records of her action are 

 not more fully preserved. Comparatively little of 

 the earth's surface has yet been scientifically explored, 

 and it is too early to say what the rocks may not dis- 

 close. 



Threefold Evidence. 



Scripture tells us, " A threefold cord is not quickly 

 broken " ; and we have three great classes of evi- 

 dence that all existing life has been developed from 

 lower forms. 



1. All living beings from the animalcule up to man 

 show a connected resemblance of forms that warrants 

 the comparison of animal life to the growth of a 

 tree ; and from sea-weed to oak tree a similar con- 

 nection of all plant life to the forms below and above 

 it shows that the same comparison may be made of 

 the plant kingdom. 



2. Each individual begins life in the lowest form 

 of matter, and develops through forms common to all 

 the species below it. A man has by turns the forms 

 of the germs of plant, protozoan, mollusc, articulate, 

 and vertebrate — fish, reptile, and mammal. 



