VI PREFACE 



worth while to reprint them ; and entertain 

 the hope that the story of their origin and early 

 fate may not be devoid of a certain antiquarian 

 interest, eveo if it possess no other. 



In 1854, it became my duty to teach the 

 principles of biological science with especial refer- 

 ence to paleontology. The first result of address- 

 ing myself to the business I had taken in hand, 

 was the discovery of my own lamentable ignorance 

 in respect of many parts of the vast field of know- 

 ledge through which I had undertaken to guide 

 others. The second result was a resolution to 

 amend this state of things to the best of my 

 ability ; to which end, I surveyed the ground ; 

 and having made out what were the main posi- 

 tions to be captured, I eame to the conclusion 

 that I must try to carry them by concentrating all 

 the energy I possessed upon each in turn. So I 

 set to work to know something of my own know- 

 ledge of all the various disciplines included under 

 the head of Biology ; and to acquaint myself, at first 

 hand, with the evidence for and against the extant 

 solutions of the greater problems of that science. 

 I have reason to believe that wise heads were 

 shaken over my apparent divagations now into 

 the province of Physiology or Histology, now into 

 that of Comparative Anatomy, of Development, of 

 Zoology, of Paleontology, or of Ethnology. But 

 even at this time, when I am, or ought to be, so 

 much wiser, I really do not see that I could have 



