VERMES THE WORMS 91 



inches long, by a quarter of an inch or a little more in 

 breadth, the scales disposed in double row, as in the shorter 

 species. 



There are many allied species, all procurable within the 

 limits of tide range, stony ground at extreme low tide 

 and the edges of Zostera fields being the best hunting 

 grounds for them. One remarkable species may be found 

 by digging in open stretches of shell gravel (Sigalion 

 arenosa.) It is of large size, six inches long by about five- 

 eighths of an inch broad. In this one the scales are obscured 

 by their being set with a fine felt arrangement, which holds 

 grains of sand closely and firmly, so that the back is like a 

 piece of coarse glass-paper. 



The Nereids are another large family. The most familiar 

 example is Nereis diversicolor. This worm grows to a 

 length of about nine inches. It takes its name from its 

 varied tints, as it gleams with reflections of red, green, 

 purple, blue, and gold. 



The use of these bright colours to an animal that usually 

 keeps hidden has been a puzzle to naturalists, for it is a 

 fairly well-established fact in Nature that strongly marked 

 characters in colour or ornament must be of use to their 

 possessor for instance, in flowers to^attract insects for 

 the transmission of pollen ; in sea anemones (probably) 

 to lure little fishes to the larder ; in birds, etc., to act, 

 smart necktielike, in entrancing the members of the opposite 

 sex. 



In many forms conspicuous colours notify to the enemies 

 of the possessor that the latter is not good to eat, or that 

 it is not safe to try to eat it. To take one example out of 

 hundreds : the common little vermilion and black or 

 rather cinnabar and black moth, that flits lazily along our 

 footpaths in the day and makes no effort to escape when 

 approached the " Cinnabar moth " this flits with im- 

 punity where birds abound and is not molested. 



