OF NATURAL HISTORY. I5i 



iiourifliment, and dlfcharges the excrement, or unprofitable 

 part of its food. When the fhellls not too large, the fea-net- 

 tle has the power of turning its infide out, and by this ftrange 

 manoeuvre the fhcll is thrown out of the body, and the ani- 

 mal refames its former ftate. Eut, when the fliell prelents 

 itfelf in a wrong pofition, the animal cannot difcharge it in 

 the ufual manner ; but, what is extremely fingular, near the 

 bafe of the cone, the body of the creature fplits, as if a large 

 wound had been made with a knife, and through this gafli 

 the Ihell of the mufcle, or other Ihell, is ejected. 



With regard to the progreffive motion of the fea-nettle, it 

 is as flow as the hour-hand of a clock. The whole external 

 part of its body is furniflied with numerous mufcles. Thefe 

 mufcles are tubular, and filled v/ith a fluid, which makes 

 them projeft in the form of prickles. By the infl:rumentali- 

 ty of thefe mufcles. the animal is enabled to perform the 

 very flow motion juft now mentioned. But this is not the 

 only m.eans by which the fea-nettle is capable of moving. 

 When it pleafes, it can loofen the bafe of the cone by which 

 it is attached to the rock, reverfe its body, and employ the 

 filaments round its mouth as fo many limbs. Stiil, however, 

 its movements are imperceptibly flow. For thefe fads feve- 

 ral authors might be quoted ; but we fliail refer the reader 

 folely to M. de Bonnet *. 



Before we conclude this chapter, we fhall jufl: mention a 

 mode of flying which is peculiar to certain infetfls. The 

 mafon-heey which is one of the folitary fpecies, has received 

 that appellation, becaufe it confl:ru(Sls a nell with mud or 

 mortar. Externally, this neft has no regular appearance ; 

 and is, therefore, generally regarded as a piece of dirt acci- 

 dentally adhering to a wall. This habitation, however un- 

 feemly in its exterior afpeiSf, is furniflied with regular 

 cells, and often gives rife to great conflicts. When the real 

 ^ Oeuvres de Bonnet, 4to edit. torn. 5, page 345, 



