SKIMMING THE SURFACE 



which have escaped to freedom in a similar manner, from 

 the stomachs of herons and other creatures which have 

 swallowed them. 



Some tropical ''puffers" are a foot long, but the fishy 

 footballs most frequently seen are much smaller, includ- 

 ing those which sometimes become comical additions to 

 aquaria. The flesh of puffers is poor, and in some cases 

 poisonous: as though they had become not merely 

 assassins but Borgias in their determination to avoid 

 being peacefully digested. 



When fully puflfed out, globe-fish turn over and float 

 upside-down, carried here and there by the waves in 

 nonchalant "touch me if you dare" attitudes. 



The trigger-fish is seldom referred to in popular books 

 on the sea, but is well worth examination. It has eight or 

 ten genera and about one hundred species, all of which 

 inhabit warm seas. A single species, however, wanders 

 northward on the Atlantic coast as far as Gape Cod. It is 

 a rather handsome fish, encased in heavy scales like a 

 knight in armour, and has three stout dorsal spines or 

 rays. When the dorsal fin is raised (it is very thick and 

 strong) it holds its elevated position and cannot be 

 pressed down. It has ''locked" itself in its extended atti- 

 tude. But if the second ray is depressed (or pufled, as a 

 trigger is pulled) the first ray instantly falls flat — released 

 as the hammer of a gun is released when the gun is 

 fired. 



Closely related to the trigger-fish is the file-fish, or 

 fool-fish. The former name has been given the creature 

 because of its rough and prickly skin, which is so abrasive 

 that it can easily take the skin from a man's hand if the 

 creature is carelessly handled. The latter name derives 

 from the fish's large, expressionless, staring eyes, which 

 give it a vacant, idiotic expression. 



Despite their coarse skins and vacuous, foolish ex- 

 pressions, file-fishes are often most beautifully tinted. 

 They have jaws of enormous strength, and can perform 



51 



