xii PREFACE 



Journal of Microscopical Science, vol. lv., 1910, 

 see pp. 36-43), also finds difficulty in differenti- 

 ating between Osborn's categories, and adds 

 that " Lankester's term, homoplasy, as origin- 

 ally defined [1870], covers all the cases." 



In the following pages I have tried to show 

 that homoplasy does not cover all the cases 

 which are included under convergence in the 

 wider acceptation of the term. 



A. WILLEY. 



LONDON, 15^ August 1910. 



