ON POISONOUS FISHES AND FISH-POISONS. 283 



hard tubercles, set in groups, or dispersed iu compartments more or less 

 regular, and stoutly rooted in a thick skin. They receive the name of 

 Balistes from the serrated spine on their back, which they can suddenly 

 elevate for defence, just as the ancient Balista was forced up with a spring 

 for the discharge of arrows. They have powerftd teeth ; in the anterior 

 two, compared to incisors, which enable them to break crustaceous and 

 testaceous animals readily ; and their flesh is said to become dangerous 

 during the season in which they feed on the coral polypi : nothing but sea- 

 weed was found, however, in those that Cuvier examined. Though possibly 

 deleterious from their description of food, it is probable their most hurtful 

 quality is to be found in the spines, furnished them by nature for their 

 defence. These spines are invested with a viscous fluid, producing inflam- 

 mation in the wounds which they cause, and may have much to do with the 

 poisonous reputation of the flesh. 



The Ostraciones, or Trunk-fishes, in lieu of scales, have an envelope made 

 up of regular compartments, set one into the other, and forming an 

 inflexible coat of mail. It so invests the head and body, that they have 

 nothing soft or moveable but the tail, the fins, the mouth, and the coriaceous 

 edging of the gill-slits. All their swimming appendages are passed through 

 holes in their cuirass. The greater number of their vertebrae are cemented 

 together, and their ten or a dozen conical teeth can break shells and 

 Crustacea with ease. It will be seen that the Ostraciones have a close 

 relation in external character with the 'Balistes. To what extent we are to 

 place reliance on the assertion that the flexible portions of the fish are 

 poisonous, especially the tail, I know not ; but inasmuch as their flesh is 

 but small in quantity, and their liver large, yielding oil considerably, and 

 their stomach membranous and voluminous, they have not been suspected 

 without reason of being poisonous. They are, with the Balistes, all tropical 

 fishes. 



The Diodons and Tetraodons are fishes of the family Gymnodontidce. 

 They both live on Crustacea and fuci. Their flesh is mucous or slimy. 

 They have a peculiar organisation, — a detached outer skin, a sort of crop, 

 which they can inflate, swimming upside down. Their air-bladders are 

 very large. The stomach of the Diodon is thin, furnished with many append- 

 ages, which, like so many small csecal pouches, contribute to the necessary 

 completion of digestion, by retarding the aliment till it be acted upon by an 

 augmented quantity of gastric juice. Their liver, thick and trilobate, 

 extends almost to the anus. 



The flesh of both Diodon and Tetraodon is regarded as dangerous food. 

 " Pison assures us that the gall is poisonous, and that if it be not removed, 

 it causes death to those who are so imprudent as to eat of the animal thus 

 prepared. Their sensibility becomes blunted, the tongue immoveable, the 

 limbs grow stiff, and life is extinguished, while a cold and a colliquative 

 sweat inundates the entire body. The wound inflicted by the prickles or 

 spines is considered dangerous. Serious accidents are experienced, if care 

 be not taken to withdraw from the viscera of these animals, when they are 



