360 THE ZOOLOGIST. 



their own making, as to distrust the evidence of my own senses 

 respecting the existence of a pre-established and duly-considered 

 system in nature, the arrangement of which preceded the creation 

 of all things that exist."* 



What we seem to require is a healthy Agnosticism in theo- 

 retical science ; neither affirmation nor negation, per se. but 

 proof. Thus, grant to all a free use of the imagination in 

 scientific theory, but in no case allow it to be confounded 

 with fact, or crystallized into dogma. " What is called 

 ' mimicry ' is apparently, in many cases, nothing more than the 

 influence of similar surroundings, acting in a similar manner 

 upon different insects inhabiting the same district." f Or, as 

 Mr. F. T. Mott most enigmatically puts the objection, " The 

 very curious appearances of mimicry, which are often supposed 

 to be protective, but of which a large proportion seem to have no 

 such function, may probably be attributed to sympathetic com- 

 munication of the vibratory motions which must be passing 

 through the ether in all directions in the neighbourhood of 

 organic life." I Animal depredators may, however, be not 

 altogether defeated by " mimicry," which of course predicates 

 the sense of sight only. As Mr. Cornish has well observed, 

 predaceous animals watch for movement to guide them to their 

 prey. " Most of the larger birds, notably Wood Pigeons, remain 

 perfectly motionless for many seconds after alighting in a new 

 place, in order to identify any moving object. On the other 

 hand, the power of scent is a great corrective to animal miscon- 

 ceptions about objects." § How little is the cause of Darwinism 

 advanced by many exhibitions made at scientific societies ! The 

 advocate exhibits — say, insects — which, belonging to different 

 orders, closely resemble each other in colour, markings, or 

 structure, and which he reasonably adduces as an example of 

 " mimicry," but misuses a suggestion as a demonstration. The 

 Darwinian sceptic at once denies the strength of the whole 

 argument, because it cannot be demonstrated as a fact, and has 

 not been put forward as a suggestion only. It is quite possible 



* ' An Essay on Classification,' p. 228. 



f W. F. Kirby, ' A Handbook to the Order Lepidoptera,' vol. iv. p. xxiv. 



\ "Organic Colour," ' Science,' June 16th, 1893. 



§ ' Animals of To-day,' p. 165. 





