PREFACE. 



THE object of the present work is to throw some light 

 on the theory of Descent. Among many of the 

 students of nature of the present day we perceive 

 that greater and greater contradictions arise between 

 the actual results of their technical work and that 

 which they put forward as ' postulates 9 of the theory 

 of Evolution. Our object is to deal with this. The 

 ' certain ' or the ' probable ' should be separated 

 from the pure ' postulates ' and the actual area of 

 elucidation of the hypotheses of Evolution be thereby 

 clearly defined. The chief postulate, the origin and 

 development of the animals from the plants, is dealt 

 with fully. 



If the area of elucidation be exactly defined, then, 

 and then only, can it be a question of a truly scientific 

 attempt at explanation. The best known systems, 

 those of Darwin and of Lamarck, are tested by their 

 premisses and method ; but only their specific doctrines 

 are taken into consideration. 



In the formation of a reliable hypothesis it was 

 less important to present a complete collection of all 

 observations than to show clearly, by separate examples, 

 the demonstrative force and extent of the argument 

 concerned. 



