The roundworm, however, is peculiar to childhood. It is a yellowish or whitish worm resembling the earthworm, from one to twelve inches in length. The body is round, tapering toward each extremity. This worm inhabits the small intestine, but by acts of vomiting they are frequently ejected from the mouth or they may find their way into other cavities. On the Pacific slope these worms are not as frequently met with as on the other side of the Rockies. It is propagated by _ova_ and taken into the system by means of drinking water containing them. The number varies greatly in different cases; sometimes there are only a few and again there may be dozens or hundreds coiled together so as to form balls or masses. They are most common between the ages of three and ten years. I do not believe that they ever exist in early infancy. The symptoms denoting the presence of these parasites are on the whole obscure and depend somewhat on the temperament of the individual. A nervous child may be thrown into fits or convulsions from them. My first case of these worms in a child seven years old was rather exceptional and remarkable. The child was suddenly taken with a severe attack of spasmodic croup, for which I prescribed remedies without much relief. After the second day the child passed five large roundworms, the croup subsided, and while I claimed no credit that my remedies did not cure the croup it was generally conceded that they killed the worms. The usual symptoms are colic pains, impaired appetite, diarrhœa, itching of the nose, swollen abdomen, puffy features, offensive odor of breath, dreaming sleep and grinding the teeth during sleep or twitching of the muscles. The expulsion of the parasite is generally effected with simple remedies. Five to ten drops of spirits of turpentine in half to one tablespoonful of castor oil is a reliable remedy. The oil of wormseed is another convenient remedy in the same dose on a lump of sugar or mixed with oil; a cupful of tansy tea early three or four mornings on an empty stomach serves a useful purpose; pinkroot and senna administered as a tea has also a well-deserved popularity. The thread, pin, spring or mawworm inhabits the large intestine and chiefly the rectum. It is a thin yellowish-white parasite from one-twelfth to one-third inch in length; the female has a straight, awl-like, pointed tail, the male has a strongly curved tail. It rarely, if ever, enters the small intestines. The worms occur chiefly in young children, but there is no period of life that is exempt from them. They cause pain and an itching sensation at the anus. This is particularly troublesome when the children lie in warm beds. The sexual organs are apt to become excited from the irritation and the habit of masturbation be thus formed. In girls the worms may travel into the vagina and leucorrhœa in children is often accounted for in this way; around the anus there may be pimply redness.