_ x1 PHENOMENA OF ORGANIC NATURE 333 
place, to the consideration of a matter which may 
seem foreign to the question under discussion. 
_ We must dwell upon the nature of the records, 
and the credibility of the evidence they contain; 
_ we must look to the completeness or incomplete- 
ness of those records themselves, before we turn to 
that which they contain and reveal. The question 
_ of the credibility of the history, happily for us, 
_ will not require much consideration, for, in this 
_ history, unlike those of human origin, there can 
_ be no cavilling, no differences as to the reality and 
_ truth of the facts of which it is made up; the 
- facts state themselves, and are laid out clearly 
before us. 
But, although one of the greatest difficulties of 
_ the historical student is cleared out of our path, 
_ there are other difficulties—difficulties in rightly 
interpreting the facts as they are presented to us 
_ which may be compared with the greatest 
difficulties of any other kinds of historical study. 
__What is this record of the past history of the 
- globe, and what are the questions which are 
involved in an inquiry into its completeness or 
- incompleteness? That record is composed of 
_ mud; and the question which we have to investi- 
gate this evening resolves itself into a question of 
_ the formation of mud. You may think, perhaps, 
that this is a vast step—of almost from the 
_ sublime to the ridiculous—from the contemplation 
a 
of the history of the past ages of the world’s 
