THE EDGE OF THE EDGE 381 



twisted the soft-bodied animal around, throwing the traihng 

 stingers out of their graceful arrangement. I gasped, rubbed my 

 arm and was interested to observe that the man-of-war in- 

 stantly retracted its tentacles, drawing them well up under its 

 partially deflated float. The expanded tentacles were fully ten 

 or twelve feet long and, had I received the full benefit of their 

 discharge I would have had an exceedingly nasty arm. As it 

 was, my arm burned and smarted for nearly two hours. 



Portuguese men-of-war are as peculiar as they are malignant. 

 They are cousins to the hydroids and the jellyfish but have 

 the distinction of being almost the only communists to live in 

 a completely beneficial yet unquarrelsome group. For men- 

 of-war, as single as they may seem, are really made up of 

 several separate individuals, all performing different functions 

 but operating as a unit. Superficially they appear as one animal 

 but if the colony is examined carefully it will be seen to be 

 composed of polyps having varied shapes and purposes. One 

 type, a tube-like structure of dehcate blue, does the feeding 

 and digesting for the entire group; another, a finger-shaped 

 jelly, is highly sensory and functions as a tactile organ; still 

 others serve as reproductive cells, while a fourth kind have 

 been metamorphosed into long tentacles and streamers loaded 

 with poisonous stings. These capture the prey and act as de- 

 fensive armament. They also serve the further purpose of bal- 

 ancing rudders. Needless to say, the Portuguese men-of-war 

 are let strictly alone. 



But the most interesting sight, after I recovered my equilib- 

 rium, was the host of tiny fish that centered about the jelly. I 

 identified them as the butterfish, Peprilis, the young of the same 

 creatures that grace our tables. They have become associated 

 with the Portuguese man-of-war and with other jellyfish, to 

 which they look for protection. When menaced by larger and 



