444 PARASITES OF ANIMALS 



following manner : A small portion of wool having been 

 dipped in chloroform and placed in front of the nostrils the bird 

 soon became insensible. The skin of the neck was then divided 

 and the trachea slit up to the extent of a quarter of an inch. 

 With a pair of common dissecting forceps, I removed seven 

 Sclerostomata. Six of these parasites were sexually united, 

 the odd worm being a female. After I had closed the external 

 wound with a single thread the bird woke out of its artificial 

 sleep, when it soon recovered its legs, and ran about the table 

 vigorously. Moreover, in a very few minutes it devoured the 

 contents of a saucer partly filled with bread and milk. An 

 occasional gape was caused by an accumulation of frothy mucus 

 within the injured trachea, but this obstruction the bird soon 

 got rid of by shakes of the head and sneezing. The only sub- 

 sequent inconvenience to the bird arose from emphysematous dis- 

 tension of the cellular tissue of the head and neck. This was 

 relieved by puncture, the emphysema ceasing to form after the 

 external wound had healed. Some months afterwards I destroyed 

 the bird, and on dissecting the neck, a distinct cicatrix was 

 found indicating the site of the operation on the trachea. The 

 divided cartilaginous rings, six in number, were united only by 

 a thin layer of connective tissue. The female worms gave an 

 average length of f", the males scarcely exceeding J". The 

 mouth is furnished with six prominent chitinous lips. In both 

 sexes the surface of the body is quite smooth, but the tail of 

 the female exhibits a tendency to fold upon itself. The 

 lower part of the body suddenly contracts to form a short, 

 narrow, mucronate, pointed tail. The male is usually found 

 rigidly affixed by means of a strong, membranous, sucker-like 

 bursa, which proceeds from the lower end of its body. In 

 regard to the peculiar mode of union of the sexes, it becomes 

 an interesting point to ascertain whether there be an actual 

 incorporation of the substance of the copulatory organs during 

 or after the act of impregnation. In my specimens none of 

 the three pairs were organically united, and I succeeded in 

 separating one pair very readily. Dujardin speaks of them as 

 being soldered together, whilst the statements of Von Siebold 

 are still more explicit. In connection with this subject the 

 latter observer makes the following comment (' Wiegmann's 

 Archiv/ 1836, s. 106) : " The two sexes of almost all round 

 worms are united only at the time of copulation. The male of 

 Heteroura androphora has also the habit of remaining connected 



