84 DISEASES OF THE HOG. 
in their motion. From experiments that have been 
made it appears that the ova are never developed 
in the animal body, but being discharged with the 
feces retain their vitality for a long time, and if 
placed in water become at the end of about eight 
months and a half developed into embryos, about 
one three-hundredth of an inch in length. It is 
probable that these are carried by the rain and 
other means into streams, wells, etc., whence the 
‘drinking water is derived and thus they become 
fully developed. There are no particular symp- 
toms by which we can detect this worm from oth- 
ers during the life of the animal, and the treatment 
would be the same as for the thorn-headed worm. 
Very often when worm medicine is given a variety 
of worms will be discharged at the same time. 
ASCARIS SUILLA (ROUND WORM.) 
This is a round, smooth worm of considerable 
size; the male usually reaches when fully devel- 
oped six inches, and the female may be twice that 
length. This worm usually does no harm when 
there are only a few present. The animal will like- 
ly keep in good health, but when they are numer- 
ous they will disturb digestion and cause colicky 
pains, loss of flesh, dry hair, morbid appetite, rest- 
lessness and nervous twitching, and in some cases 
fits. Cases are recorded in which they worked 
through the walls of the intestines and, reaching 
some of the other organs of the body caused death.. 
This worm generally inhabits the small intestine, 
but not infrequently finds its way forward to the 
