viii PREFACE. 
If the style in which I have written be somewhat 
varied, it must be borne in mind that the conditions 
under which the writing has been done have also been 
varied, and this must be my apology for any deficiency 
which may be found in its pages. Most of the chapters 
have been written off without the opportunity of reference 
to other books. Several of them have been penned whilst 
crossing the Atlantic, some in railway station waiting- 
rooms, often during a midnight wait, or in the early 
hours of the morning. A part was written at sea in the 
‘cabin of a trawler, and the rest has been put together 
amidst the scenes of a very busy life. For my know- 
ledge of the subject Iam indebted largely to my own per- 
severance, and determination to understand thoroughly 
that which I had taken up as my life’s work, as well as 
to many fellow-labourers in the same field, who have 
given me the benefit of their knowledge. 
It is interesting to look back upon the work of thirty 
years that have passed away, and to note how one has 
been led, and how the work has developed, at times 
under considerable difficulties, until it has reached its 
present magnitude. The present seems a fitting oppor- 
tunity for tendering my warmest thanks to some of those 
who have aided me in my investigations of so fascinating 
a subject. To the late Frank Buckland I am indebted 
for my first introduction to the study, and to the late 
