COASTLINES 



bladder-like float, which bobs about on the surface of 

 the waves. From its "hull" masses of multi-coloured 

 streamers descend below the surface. These may be as 

 much as fifty feet long, and though they look harmless 

 enough they are stinging tentacles. 



The "hull" or "float" is a bag, sometimes a foot long, 

 filled with gas which serves to keep the colony on the 

 surface. By contracting itself it can discharge some of the 

 gas, so that it can sink a little below the surface; or it 

 can expel most of its gas through a pore (or "valve") 

 enabling it to submerge completely. 



The streamers, or tentacles, have various duties. Con- 

 trary to many superficial descriptions of the man-of-war, 

 they are not all stinging tentacles : in fact only a few of 

 them, comparatively, have stinging contrivances. Those 

 which serve as "marines" or "guards" are so armed, and 

 these have lasso-like devices which cling tightly around 

 their prey and draw it towards a number of squirming 

 siphons. Thousands of stinging barbs have been released 

 — as though the "ship" had fired numerous torpedoes — 

 which poison the victim and render it helpless. The 

 mouths are sticky and cling to the prey on all sides, until 

 it is at last enclosed, as though in a tight bag. It is then 

 digested and carried into the stomachs of the siphons. 



The stinging barbs need special mention. Each barb — 

 and the "ship" carries thousands of them on its fighting 

 tentacles — resembles an inverted tube, coiled up like a 

 spring in a microscopically small box, which is covered 

 by a lid. Attached to each box is a trigger-hair. Imme- 

 diately this is touched it is stimulated chemically : the lid 

 flies open and the inverted tube within the box shoots out 

 with lightning-like rapidity, turning inside out as it flies, 

 and so exposing the vicious, pointed spines which had 

 been concealed in the inverted form of the tube. Im- 

 agine the finger of a glove, with spikes on the outside. 

 Turn it inside-out and you have the spikes pointing 

 inwards — the position of the stinging barbs before release. 



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