44 SPOLIA ZEYLANICA. 
the easier it is to make a rule about them, or, to use an analogy 
invented by the late Professor W. K. Clifford, it is simpler to 
put a room in order when it contains little furniture than 
when it contains much furniture. Or, again, if you have only 
ten books you may classify them without trouble, bat to 
adequately arrange a library of 10,000 books is a very different 
matter. We should, therefore, not be content to accept the 
perfect all-explaining theory without a thorough investiga- 
tion of the facts to which it pertains ; in other words, be wary 
of the obvious. Nothing could be more obvious than that the 
sun goes round the earth, but for all that it does not. 
There is still another pitfall in the path of natural history, 
and that is the want of precise definition of scientific terms. 
Thus, for example, the voluminous literature which has 
appeared dealing with the inheritance of acquired characters 
is to a large extent the result of the elasticity of the single 
term ‘‘acquired.”’ 
Herbert Spenser’s admirable phrase ‘functionally pro- 
duced modifications ”? had been, it would seem, lost sight of. 
Then, again, much confusion has existed among biologists 
whose interests were with questions of inheritance, owing to 
the inability to perceive the difference between a statement 
which applies to masses and a statement which applies to 
individuals, and also to the want of distinction between a 
statistical and a physiological law. 
Progress has more than once been hindered by the want of 
investigation of the common sense interpretation of things. 
Thus, for a lengthy period every one was quite sure that bodies 
of different weight, if dropped, would fall at different rates. 
It stands to reason, of course, that if you drop a ball of iron 
and a wooden door handle at the same moment from a point 
of some elevation, the ball of iron will reach the bottom first ; 
and that is what everybody thought till Galileo took the 
trouble to drop a few articles from the top of the leaning tower 
of Pisa, thereby proving everybody to be wrong. 
Perhaps I cannot do better in this connection than to quote 
that brilliant investigator, Mr. A. D. Darbishire. He says, 
in conclusion to an argument, ‘“‘ The cifference between 
expectation based on this law (he is referring to a certain law 
