Children, we know, are more liable to have these parasites than adults, with the exception of the tape-worm; particularly is this the case with those of the labouring and agricultural classes, and with children who are fed upon rich dainties. With regard to the agricultural class, it is, I think, easily explained. People who live in the country—I refer, of course to the poorer sort—allow their children to run about wherever they please, especially in the spring and summer time; the cottage door and the small garden are generally the places where they assemble; or the neighbouring lane or meadow, if the weather is at all favourable; where they may be seen rolling and tumbling about, picking up what they can find if at all edible, and soon putting their discoveries into their mouths with apparent relish. The British cottagers, not being at all particular as to whether their vegetables are clean or not, swallow, as well as their children, any insect that may be ensconced in the half-cooked cabbage, or unwashed celery or water-cress. Another reason is, I think, of more weight than the preceding two, and that is, they very seldom think of using salt at meal-time, though it is sometimes to be seen on their tables. The English working-classes are nearly, if not altogether, unacquainted with the benefit of salt, and very few indeed utilise it as they should; so that we can easily understand why they are so infested with intestinal parasites, which thrive in such a soil, and increase, in some instances to an enormous extent. The embryo of the tape-worm, called the _echino-coccus hominis_, in such cases finds a fitting and a secure home, and soon develops into its tape-like form, and with wonderful tenacity keeps firm hold; so that sometimes it is difficult, or even impossible, to effect its entire removal, especially if it has existed for any length of time, and particularly if the individual indulges often in pork; for as its source is undoubtedly measely pork, such a course of diet nourishes it and imparts an increased vitality. I have known them to exist in some people notwithstanding the most energetic and judicious treatment, not only for many years, but for a lifetime; and in the end to cause the death of their victim. Sailors, by reason of their wretched diet, are frequently troubled with this parasite. Whenever these intestinal parasites exist they are indicative, not only of foul diet and abstention from salt, but also of impure habit, and prove conclusively that the individual is more or less a stranger to salt. The latter is more commonly the origin of these pests, and shows us how careful we ought to be as to what we eat; for we may well suppose that the ingestion of pork, vegetables half-washed, and abstention from salt is just the kind of diet favourable for the reception of the embryo, and for its speedy development.