68 



its intended exit through a perforation of the skin, known by various 

 symptoms which it is needless here to describe. The point of exit 

 is usually marked by circumscribed inflammation and suppuration ; 

 aud the prolonged and tedious extraction of the worm is usually ac- 

 companied throughout with a good deal of suppuration and pain, ac- 

 cording to the situation and relations of the part affected and the 

 habit of the patient, and also in a great degree according to the mode 

 in which the artificial extraction is proceeded with. 



The worm invariably presents itself with the head first. On this 

 account, unless an opportunity (which rarely occurs) be afforded of 

 seeing the case before the pustule by which the point of the crea- 

 ture's exit is indicated be opened, the head is usually rubbed off and 

 destroyed. Out of many cases occuring in this country I have only 

 once succeeded in obtaining a perfect cephalic extremity of the 

 worm. The caudal extremity is thus of course always the last to 

 come away, and I have had abundant opportunities of examining this 

 portion of the animal. 



The whole worm, when mature and fresh, is of a transparent, 

 milky white colour, and presents an indistinct, brownish, wavy, lon- 

 gitudinal streak ; it is cylindrical, and about -^ of an inch in diame- 

 ter, and as I have stated, from four to six feet in length. The surface 

 is marked by distinct and regular transverse or circular rugas, which 

 are more or less approximated according to the degree of extension 

 in which the worm may be placed. In consistence it is tough and 

 elastic to a remarkable degree ; so much so, that when quite fresh, a 

 portion admits of being elongated to nearly double its natural length. 

 When dried the body assumes a flattened, riband shape, like all the 

 nematoid worms with two opposite bands of muscle, and it becomes 

 horny and transparent. The cephalic extremity is obtuse and 

 rounded, and presents a minute oral orifice, around which the exter- 

 nal integument appears to be thrown into radiating folds. But I 

 have not made as accurate an examination of this part as I could 

 have wished, owing to the difficulty of procuring specimens with that 

 extremity in a perfect state. The body presents the characters de- 

 scribed above. The caudal extremity is more or less acuminated, 

 -subulate and curved, as shown in Figs. 1, 2, 3, 4, 5. Tn conse- 

 quence of the varieties presented in the form of this part, it has been 

 formerly erroneously described as affording a distinguishing sexual 

 character. But that, in reality, it affords no such character, is suffi- 

 ciently obvious when it is remarked that all the varieties of the cau- 

 dal extremity occur in individuals containing living young, and 



