BODILY CHARACTERISTICS— CONSPICUOUSN ESS 309 



the stinging-cells with which these creatures are richly endowed 

 make them very undesirable morsels. The bright hues of many 

 Jelly- Fishes are similarly associated with cells of the sort, and 

 these creatures have been aptly styled "sea-nettles". Although 

 Sponges are not provided with stinging - cells they are often 

 extremely malodorous, and the sharp limy or flinty spicules which 

 abound in their tissues cannot add to their acceptability as an 

 article of diet. Their unpleasant properties are commonly asso- 

 ciated with bright colours, orange being a favourite tint. 



SPURIOUS WARNING OR MIMICRY 



Genuine Warning having now been briefly considered, we may 

 turn to a class of facts coming under the head of Spurious Warning 

 or Mimicryc This embraces cases where an animal devoid of any 

 noxious qualities resembles in form or colour, or both, some other 

 creature which is notoriously unpalatable and advertises this fact 

 by means of warning coloration. It is scarcely necessary to recall 

 a statement made elsewhere to the effect that the so-called mimicry 

 is a purely unconscious process. We are here only concerned 

 with the fact that such mimicking forms would appear to benefit 

 more or less by their resemblance to such well-defended species, 

 being probably treated with respect by natural enemies which would 

 otherwise be pressing in their attentions. It may, however, be as 

 well to state here that there has been too great a tendency to 

 assume offhand that given animals are illustrations of mimicry, 

 warning coloration, or what not, without making them the objects 

 of careful experiment. As a matter of fact the meaning of colours 

 or markings in particular cases is often obscure, and it is better 

 to suspend one's judgment than to come to a hasty conclusion. 



Mimicry among Vertebrates. — Wallace (in Darwinism) 

 cites the resemblance between Cuckoos and certain other Birds as 

 an instance of imperfect mimicry, and that between East Indian 

 Orioles and Friar Birds as a more perfect example of the same 

 phenomenon. Cuckoos are not well provided with the means of 

 defence, and it is remarkable that the Common Cuckoo is not 

 unlike a Sparrow-hawk in appearance and mode of flight, while 

 other species are known which are liable to be mistaken for 

 Drongo-shrikes, Starlings, and Pheasants respectively. All the 

 forms supposed to be mimicked are more powerful and less liable 

 to be attacked than the Cuckoos which resemble them. 



