The one most natural question to which, in every instance, the doctor has to reply is this: 'Will he or she outgrow it?' To this the answer is, '_Yes_,' and '_No_.' In the worst cases the answer is obviously _no_; and in none does _yes_ imply a recovery so complete as to leave no trace behind, and to make the child heartwhole. But short of this, in many instances much may be hoped for. There is, as I shall have occasion again to repeat, a power in the growing heart to adapt itself in large measure to conditions other than those of perfect health. The channels, through which the blood ought not to flow, may shrink though they may not entirely close; the valve may shut more completely than at first the opening between the two sides of the heart; all inconveniences may lessen, and the child may at last become scarcely aware of the difference between himself and others. But for any such result, or for anything approaching it to be attained, certain conditions are absolutely essential which it is seldom easy to induce parents to observe. Whatever can hurry the circulation is most carefully to be avoided. The child must be kept strictly out of the way of hooping-cough, measles, or any other fever; must be shielded from every risk of catching cold, and having smaller power of maintaining its warmth than others have, must be specially warmly clad, and must live in rooms at a temperature of 60 deg. Fahr., all the year round. Great attention must be paid to the state of the bowels, so that constipation may not necessitate violent efforts to relieve them. Moreover, for years the child must be carried upstairs; when old enough to take part in games, it must not be allowed to join in any which call for violent exertion, such as cricket, or lawn tennis, nor ride any other than a quiet pony at a gentle pace. It depends entirely on the parents whether, for the sake of a very great but far-off good, they will strictly observe these rules. The difficulty will not arise on the child's part, for it is not hard for those who have had charge of it from babyhood to bring it up to quiet pursuits and quiet amusements, till it seeks no others, and, like the little cage-bred bird, does not care to emulate the flight of others stronger on the wing.