WARNING COLOURS 105 



somewhat strained, yet there is plenty of satisfactory 

 evidence to show that while certain species of animals 

 are, like soldiers in khaki, saved from their enemies 

 and disguised from their victims by being coloured 

 in tone with their immediate surroundings, there are, 

 on the other hand, animals of a certain sort that are 

 protected from molestation, like lepers, by being 

 marked in some conspicuous manner. These 

 ''warning-coloured" species are commonly nasty, and 

 the theory is that by being obtrusively marked, they 

 are, after one or two painful lessons, left severely 

 alone by enemies who might otherwise try to eat 

 them. A few of these unpleasant individuals must, 

 of course, from time to time fall victims to the 

 curiosity of inexperienced enemies, but the result is 

 beneficial to the species as a whole, for every indi- 

 vidual that is killed will give to that enemy of the 

 species a lesson which will not soon be forgotten. At 

 least one instance of what I think must be warning 

 colouration may be noticed on the reefs of Great Coco 

 Island. It is a little species of sea-snail [Bttlla), 

 whose coat of emerald green, spangled with bright 

 orange spots, attracts the eye like a meteor ; but it 

 has a most pungent and disgusting smell of musk, 

 which, I fancy, must make it quite uneatable. Some 

 that I collected and put in my stock pickle-jar gave 

 all the contents a most unpleasant and enduring 

 taint. 



