LOPHOBRANCHII AND PLECTOGNATHI. 581 



to the necessary completion of digestion, by retarding the 

 course of the alimentary matters. Their liver, thick and 

 trilobate, extends almost to the anus. 



The diodon holocanthus lives in all the seas between the 

 tropics. Like the atinga it gives itself up to very violent and 

 rapid movements when it finds itself taken, and particularly 

 when it has bit at the hook. It inflates and compresses 

 itself alternately, erects and inclines its darts, raises and 

 lowers itself with rapidity, to disengage itself from the hook 

 which retains it : it is exceedingly dangerous to take hold 

 of it. 



It appears that it is fished for in the Red Sea, and in that 

 of Japan. 



According to Father Dutertre, it is necessary in catching 

 this fish, to bait the line with a crustaceous aniunil. It ap- 

 proaches the bait at first with caution, tastes it, retires, comes 

 back, and finally swallows it ; as soon as it finds itself 

 hooked, it swells up like a balloon, sends forth a dull sound, 

 like the turkey-cock, when he makes the wheel, and becomes 

 exceedingly furious. But soon, finding its efforts useless, it 

 has recourse to stratagem. It lowers its spines, disinflates 

 itself, and becomes as flabby as a wet glove. It does not 

 resume its activity until it perceives that the fisherman is 

 drawing it towards him. 



The Diodon hystrix, which Commerson observed in the 

 living state, in the bay of Rio Janeiro, is also found near the 

 Cape of Good Hope, and at the Molucca Islands. Its flesh 

 is a species of food more or less dangerous, at least in certain 

 circumstances. Its exuvia was formerly suspended to the 

 ceilings of cabinets of natural history, and in the shops of 

 apothecaries and druggists. 



The Tetraodon also derives its name from the number 

 of its teeth, which are four. The fish of this genus, like those 

 of the preceding, are distinguished by the faculty of inflating 



