PREFACE. 



For many years past I have been engaged in 

 researches into the structure and development of the 

 vertebrate skeleton, and the results of these investiga- 

 tions have, from time to time, been published in the 

 Transactions of various Scientific Societies naturally, in 

 technical language. The Hunterian Lectures also of 

 former Sessions, which preceded the present course, 

 were delivered in the terms of Biological Science, and 

 were thus, of necessity, unintelligible to persons not 

 familiar with studies of this kind. 



During the last year or two, however, many useful 

 suggestions w^ith regard to a more popular method of 

 treating these matters have been made to me by my 

 esteemed friend, best known to the reading world as 

 Miss Arabella Buckley. To her I am indebted for the 

 plan of this last course. 



The following Lectures, therefore, I offer to my non- 



