PREFACE. IX 



To Mr. W. B. Blakeney, B.K, I am personally indebted for 

 various arrangements made at home by him, during the voyage, 

 for my benefit. 



I have, finally, to thank my friend Prof. E. Bay Lankester, 

 Fellow of Exeter College, for assistance and advice received 

 during the progress of this book; and also my friend the 

 Bev. Thomas Sheppard, B.D., Fellow of Exeter College, for 

 having kindly read through all the proof sheets, and assisted in 

 their correction. 



Exeter College, Oxfoed, 

 December, 1878. 



