52 STRICTLY INCOG. 



hereditary predilection, it must necessarily happen that the 

 more brightly coloured or obtrusive individuals will most 

 readily be spotted and most unceremoniously devoured by 

 their sharp-sighted foes, the predatory fishes. On the other 

 hand, just in proportion as any particular pipe-fish happens 

 to display any chance resemblance in colour or appearance 

 to the special seaweed in whose folds it lurks, to that ex- 

 tent will it be likely to escape detection, and to hand on its 

 peculiarities to its future descendants. A long-continued 

 course of the simple process thus roughly described must 

 of necessity result at last in the elimination of all the most 

 conspicuous pipe-fish, and the survival of all those un- 

 obtrusive and retiring individuals which in any respect 

 happen to resemble the fucus or coralline among which 

 they dwell. Hence, in many places, various kinds of pipe- 

 fish exhibit an extraordinary amount of imitative likeness to 

 tixe sargasso or seaweed to whose tags they cling ; and in the 

 three most highly developed Australian species the likeness 

 becomes so ridiculously close that it is with difficulty one 

 can persuade oneself one is really and truly looking at a 

 fish, and not at a piece of strangely animated and locomo- 

 tive fucus. 



Of course, the playful pipe-fish is by no means alone in 

 his assumption of so neat and eliective a disguise. Pro- 

 tective resemblances of just the same sort as that thus 

 exhibited by this extraordinary little creature are common 

 throughout the whole range of nature ; instances are to be 

 found in abundance, not only among beasts, birds, reptiles, 

 and fishes, but even among caterpillars, butterflies, and 

 spiders, of species which preserve the strictest incognito. 

 Everywhere in the world, animals and plants are perpe- 

 tually masquerading in various assumed characters ; 

 and sometimes their make-up is so exceedingly good 

 as to take in for a while not merely the uninstructed 



