xv THE RELATION OF FACTS TO THEORIES 321 
to such authoritative criticism ; and the fact that 
those here submitted have not stood the ordeal 
furnishes a strong presumption that a large number 
of the cases contained in the literature of the subject 
are likewise valueless. The term mimicry is applied 
indiscriminately to all cases of colour resemblance; 
many of these can certainly not be so explained, 
therefore we are justified in saying that at the 
present time the explanation of the facts of colour 
resemblance implicit in the use of the term “ mimi¬ 
cry ” is insufficient, or to use Mr. Sedgwick’s term, 
inadequate. Mr. Sedgwick’s observations in regard 
to the cell-theory seem indeed eminently appli¬ 
cable throughout to the theory of mimicry. “A 
theory to be of any value must explain the 
whole body of facts with which it deals. If it 
falls short of this, it must be held to be in¬ 
sufficient or inadequate; and when, at the same 
time, it is so masterful as to compel men to look at 
nature through its eyes, and to twist stubborn and 
unconformable facts into accord with its dogmas, 
then it becomes an instrument of mischief, and 
deserves condemnation, if only of the mild kind 
implied by the term inadequate ” (“ Remarks on 
the Cell Theory,” Compte Rendu , 3me, Cong. Zool. 
Leyde, 1896, p. 121). 
2. Protective Resemblance .—Although mimicry is 
commonly said to be merely a special case of pro¬ 
tective colour resemblance, it is in some respects 
more difficult to understand than the latter, and it 
is not perhaps necessary to suppose that the two 
stand or fall together. It is, of course, to be clearly 
understood that the existence of resemblances between 
