t 3* } 



refpire through pores placed on the fides 

 of their bodies, and which are termed 

 fpiracula ; their fkin is externally hard, 

 and ferves them inflead of bones, of 

 which they have internally none. From 

 this definition, the acus marina is evi- 

 dentlyno infecl. Butthe antennaeplaced 

 on the.fore part of the head, confti- 

 tute the principal diftinction. Thefb 

 are jointed and moveable in every part, 

 in which they differ from the horns of 

 •other animals ; they are organs con- 

 ■veying fome kind of fenfe; but we have 

 no more idea what this kind of fenfe is, 

 than a man has, who, without eyes, at- 

 tempts to determine the particular ac- 

 tion of the rays of light on the retina 

 of the eye, or to explain the changes 

 which from thence take place in the 

 human mind. That they are the oro-ans 

 of fome kind of fenfe, is apparent from 

 their perpetually moving themforward ; 



yet N 



