X ON THE STUDY OF BIOLOGY 279 



the light given out by the crackling of thorns under 

 a pot of which Solomon speaks. So far as I re- 

 collect, Solomon makes use of the image for 

 purposes of comparison ; but I will not proceed 

 further into that matter. 



Two things must be obvious : in the first place, 

 that every man who has the interests of truth at 

 heart must earnestly desire that every well- 

 founded and just criticism that can be made should 

 be made; but that, in the second place, it is 

 essential to anybody's being able to benefit by 

 criticism, that the critic should know what he is 

 talking about, and be in a position to form a 

 mental image of the facts symbolised by the words 

 he uses. If not, it is as obvious in the case of a 

 biological argument, as it is in that of a his- 

 torical or philological discussion, that such criticism 

 is a mere waste of time on the part of its author, 

 and wholly undeserving of attention on the part 

 of those who are criticised. Take it then as an 

 illustration of the importance of biological study, 

 that thereby alone are men able to form something 

 like a rational conception of what constitutes 

 valuable criticism of the teachings of biologists. 1 



1 Some critics do not even take the trouble to read. I have 

 recently been adjured with much solemnity, to state publicly 

 why I have "changed my opinion " as to the value of the 

 palseontological evidence of the occurrence of evolution. 



To this my reply is, Why should I, when that statement was 

 made seven years ago ? An address delivered from the Presi- 

 dential Chair of the Geological Society, in 1870, may be said to 



