54 OF THE PRINCIPAL WORMS 



ual the sex is distinct : the male is smaller and 

 shorter than the female. 



Its colour is white, sometimes resembling flesh 

 colour. The canal, which passes through the ab-. 

 domen of the worm, is yellow and transparent. 

 Goeze[i9'S) regards this as a characteristic sign of 

 this species. But this circumstance can be nothing 

 more than accidental, because this canal being the 

 alimentary tube, its colour must change with that 

 of the substances it contains. Hence its appear- 

 ance is sometimes white, black, yellow, ect.*^ 



The whole surface of the body is wrinkled and 

 annular, and tapers to both extremities. Most 

 naturalists have supposed that the circular fibres 

 embraced the whole circumference of the body, 

 Werner has however demonstrated that the fv ur 

 longitudinal fibres arc the only ones which per- 

 vade the whole superficies of tiie worm, and that 

 those reputed circular are mere fragments of trans- 

 verse fibres, which inclose the longitudinal fi- 

 bres. ( 11^9) 



This arrangement of fibres in the lurabrico'ides 

 is precisely like that of the human intestine colon : 

 for this reason, Werner considers all the fibres 

 which form the surface of this worm, as true lon- 

 gitudinal and lateral muscles ;(200; and, in this 

 way, he very well explains the serpentine motions 

 of its body. 



* In some lately examined, the colour of this tube was pur- 

 plish. These were expelled without life, and exhibited this ap- 

 pearance twelve hours after being discharged. t4. T. 



