EVOLUTION IN THE PAST 



INTRODUCTION 



The conditions under which life first became manifest on 

 earth are quite unknown. All attempts to reproduce them 

 have failed ; and even if the conditions, or likely conditions, 

 were ascertained, the mystery of life would not be solved. 

 Indeed all phenomena present unfathomable problems, and 

 man in pursuit of knowledge must needs limit the range of 

 his researches. Wide fields, however, still are left him ; 

 and in his endeavour to trace the steps by which life, once 

 initiated on earth, attained its present development, he 

 has not been unrewarded. 



No one supposes that life, when it first appeared on the 

 globe, presented, as now, a series of graduated forms, ranging 

 from specks of animated matter to human beings. It is felt 

 that life-forms of simple type must have come first ; and 

 that these were followed in orderly sequence by organisms 

 becoming less and less simple, until in time forms of high and 

 of ever-increasing complexity appeared. 



The doctrine of Evolution that the higher organisms have 

 been evolved step by step from lower organisms is now 

 generally accepted. The thought that life had developed in 

 some such continuous and connected manner dawned on the 

 mind of man centuries ago ; and Aristotle, Lucretius, and 

 other ancient writers gave vague expression to it. In recent 

 times Goethe, Erasmus Darwin, and Lamarck all believed in 

 Evolution, and enunciated clear ideas on the subject. They 

 had, however, no convincing evidence to offer. This, as the 

 result of long and patient observation, was suppUed by 



