10 EVOLUTION. 



ence by the operation of natural causes, it seems fol- 

 ly to deny that all may have arisen in the same way." 

 Although gaps still exist and missing links are looked 

 for, descent is traced, in Huxley's words, '* not in one 

 straight series but by many roads, step by step, gra- 

 dation by gradation, from man at the summit to 

 specks of animated jelly at the bottom of the series "; 

 or, as Prof. Clifford expresses it : '* The theory is, that 

 at a stupendous distance of time all species were 

 alike, mere specks of jelly ; that they gradually 

 diverged from each other and got more and more 

 different, till at last they attained the almost infinite 

 variety that we now find." 



Thus by observation of living animals and of their 

 fossil remains we find that, although for convenience 

 naturalists arrange animals into six or seven large 

 divisions, there are many forms coming between 

 these divisions, and it is hard to say where one be- 

 gins or another ends. There is, therefore, evidence 

 of the unity of all animal life, — a sufficient resemblance 

 and connection to make it extremely probable that a 

 relationship exists between all, and that they have 

 sprung from a common origin. 



/ The Unity of Plant Life. 



Plants are divided into two great classes, the flower- 

 less and the flowering. These are again divided in- 

 to four classes, having hard names, and there are 

 further subdivisions. It is found that the plant world 



