142 



PORCUPINE DIODO^ 



Diodon hystrix, Bloch. 

 PLATE XVI. 



Represents this structure. These fish are harm- 

 less inhahitants of the ocean, and possess a power 

 which is an indispensable accessory to render effi- 

 cient the weapons which have been thus allotted to 

 them. When undisturbed, or making their way- 

 through the waters, their form is longitudinal, and 

 the spines He flat on the common integument; but 

 on the approach of danger, or upon sudden alarm, 

 they can inflate the body nearly to the form of a 

 globe, w^hich places the spines erect and stifily set, 

 and renders them, in truth, a most formidable re- 

 sistance against every aggressor. The species which 

 we represent frequents the seas of the tropics, and 

 is said to feed on the Crustacea and echinodermata. 

 The wounds of the spines are by some considered 

 poisonous, or to leave a painful and inflammatory 

 wound, and which may act in the same manner 

 with the pricks from the spines of the Trachini 

 on various constitutions. 



In addition, however, to these provisions for 

 defence which are hberally fui'nished to those spe- 



