64 



THE STORY OF LIFE IN THE SEAS. 



modification of the three front spines on the 

 back, to which their name is due. It is not 

 known precisely how they act, but they probably 

 form an effective weapon of defence. In the 

 same family of Fish we frequently find on each 

 side of the tail two or three rows of sharp spines, 

 which may also be regarded as defensive. In 

 the family of the Surgeons there is only one of 



FIG. 21. Globe-fish. 



these spines on each side of the tail, and it is 

 much larger than any of those in the Trigger- 

 fish, and capable of being folded down into a 

 case in the skin like a clasp-knife. It is said 

 that these spines are connected with a poison- 

 gland, and can give very severe and painful 

 wounds, like the poison spines of our European 

 Sting-rays and Weavers. 



