GUINEA WORM. 377 



1. Hair-worm, 

 Gordius aquaticus. Linn. 

 This resembles a horse-hair in its shape, and is hence often de- 

 nominated horse-hair worm, or seta equina. It inhabits soft 

 stagnant waters, is from four to six inches long ; and twists itself into 

 various knots and contortions. Linnaeus asserts, that in Sweden 

 its bite or sting is supposed to produce the complaint called a 

 whitlow, and that he once knew this rumour verified : and Dr. 

 Shaw declares that he also once behelrt the complaint follow upon 

 the sting of a gordius, though he leaves it doubtful whether the 

 complaint might not have occurred, if the sting bad not been 

 inflicted. 



[Nat. Miscel. Turton. Linn. 



2. Guinea Worm. 

 Filaria medinensis. 



In this genus of worms the body is round, filiform, equal and 

 quite smooth ; mouth dilated, with a roundish lip. There are eigh- 

 teen species ; 



A. infesting mammals. 



B. birds. 



C. insects when perfect. 



D. insect larves. 



The division A. is found in different varieties in man, the eel. 

 lular membrane of the horse, in the lion, the martin, and hare. 

 B. In hawks, owls, crows, storks, and poultry. C. In the scara- 

 bseus fimetarius; silpba obscura, carabas, and gryllus. D. In the 

 papilio articae; p. betulae ; p. quercus ; sphinx Euphorbia ; phalaena 

 caja ; ph. quercus ; ph. pellionella ; found under the skin of the 

 larves, and very destructive to them ; sometimes solitary, and from 

 four to seven inches long. The species chiefly worthy of notice is, F. 

 medinensis, of the division A, is the dracunculus, or Guinea-worm. 

 The body is entirely pale \ellowish. It inhabits both the Indies, 

 and is frequently in the morning dew, whence it enters the .ji.ked 

 feet of the slaves, and creates the most troublesome itching*, gene- 

 rally accompanied with inflammation and fever. It must be cau- 

 tiously drawu out by means of a piece of silk tied round its head : 



