POLYPS 23 



spicuous object, being of a vivid azure blue topped with 

 pink. Long bright blue tassels of stinging cells depend 

 from the disc for several yards beneath the float and upon 

 coming into contact with a living object at once contract 

 and draw the prey, paralysed and unresisting, up to the 

 many " mouths." 



As with a large number of other members of this and 

 allied orders, the Man-of-war provides for a number of 

 " gate-crashers." Chief of these are certain small fishes 

 which live amongst the deadly stinging cells apparently 

 enjoying their protection. The stinging powers of the 

 Man-of-War are more severe than those of any other 

 known Jellyfish, and in tropic seas native pearl and sponge 

 divers dread them even more than they do the shark. 



It may be not inappropriate here to offer a word of 

 explanation regarding the stinging properties common to 

 all creatures under consideration in this chapter. The 

 small Sea Anemone or Jellyfish may cause no more than 

 a tingling sensation to the human hand, but the same 

 creatures can spell death to small animals. This paralysing 

 influence is exerted by myriads of minute mechanisms, 

 each one a miniature replica of the old-time harpoon 

 with its attached rope. When highly magnified, a stinging 

 cell is seen to consist of a double-barbed dart attached 

 to a neatly-coiled thread, the whole enclosed in a compact 

 ovoid capsule. At the small end of the capsule is a spring 

 trigger arrangement and this being touched by some foreign 

 body automatically releases barb and thread with con- 

 siderable force. 



The Sgpho^oa or true Jellyfishes when adult swim freely 

 in the open sea. The common Moon Jelly (Aurelia), 



