EDITORS' PREFACE TO SECOND 

 VOLUME 



We have wished to add a few words in order to thank those 

 who have kindly helped us in rendering the last Essay on 

 Amphimixis, which presented exceptional difficulties, accounting 

 lor the delay in the appearance of this volume. Early in the 

 present year one of us had the opportunity of consulting Pro- 

 tessor Weismann and bringing under his notice all the most 

 difficult passages in the four essays. As a result of this, the 

 English translation has been modified in some few respects, 

 and, to this extent, represents Professor Weismann more 

 accurately than the original German. We desire to express 

 our warmest thanks to him and to Fraulein Diestel for the 

 great trouble they have taken in assisting us. 



In this country our chief thanks are due to Miss Lilian J. 

 Gould, who not only translated the First Essay, but carefully 

 read through the proof sheets of the Essay on Amphimixis, and 

 made manj^ valuable suggestions. We have also been helped 

 on special points by Professors E. Ray Lankester, S. H. Vines, 

 and F. Gotch, and by Mr. D. G. Ritchie. Other kind assistance 

 has been acknowledged in our Preface to the Second Edition, 

 in Volume I. 



In conclusion, we venture to express the hope that these new 

 essays may deepen the interest already aroused by Professor 

 Weismann's earlier writings. If this be so, we shall always 

 remember with pleasure the time and work which have been 

 devoted to the production of these Essaj^s in their present form. 



E. B. P. 



A. E. S. 

 Oxford : May, 1892. 



