PREFACE. 
Were I to say, “this is a very interesting little book,” 
many would conclude that I was nearly allied to a well- 
known bird, whose mouth is so often filled with the praise 
of its own beauty. And yet I might say so without the 
slightest vanity; for I shine by borrowed light, and for 
nearly all that is interesting in the book I am indebted to 
my talented scientific friends and precursors. I have been 
like the bee—not making, but gathering honey. Like 
the bee, I have formed the cells, and had I been able to 
equal her in skill, I might well have been pleased with my 
workmanship. But though inferior in skill, I have not, 
during the progress of the work, been inferior to her in 
