and the seat of abnormal sensations, evidenced by the tendency to bite upon any object that comes to hand; in other words, there is a condition of mild catarrh of the mucous membrane. The consequent discomfort, though, is not sufficient to interfere with the child's appetite, good humor or sleep, and when, after a few days, the margin of the tooth is free, all the local symptoms vanish.

Examples of Variations.-Abnormal dentition is manifested either by departures from the laws of development already stated, or by actual difficulty in the process of cutting.

The standard rules for the eruption of the teeth may be departed from in three ways:

1. The appearance of the teeth may be premature. Children may be born with one or more of their teeth already cut; these are usually imperfect, and soon fall out, to be replaced, at the proper age, by well-formed milk teeth. Sometimes, however, they remain permanently, as in a case that came under my own observation. Natal teeth are always incisors. Instances of the lower central incisors being cut in the third month are not uncommon. Girls are more apt than boys to cut their teeth early, and, as an early dentition is likely to be an easy one, the occurrence is to be looked upon as fortunate.

2. Dentition may be delayed. This deviation is

more frequently seen and of more consequence than the first. Bottle-fed babies, as a class, are more tardy in cutting their teeth than those reared at the breast. With such, though healthy in every respect, a delay of one or two months is a common and not at all serious event. On the contrary, whatever the method of feeding, if no teeth have appeared by the end of a year, it may be assumed that the child's general nutrition is faulty, or that rachitis is present. Delay does not necessarily imply difficulty in cutting the teeth, though the two conditions are often associated.

3. The teeth may appear out of their regular order. Bottle-fed infants are most likely to show this irregularity, which is of some importance as an indication of general feebleness. In other instances, however, it is merely a family peculiarity, and, as such, bears no special significance.

Difficult dentition gives rise to two classes of affections, viz., local, and sympathetic or reflex. Difficulty, like delay, is more apt to occur in hand-fed babies than in those nourished entirely from the healthy breast, but beyond this it is impossible to prognosticate the ease or difficulty of dentition. The author has frequently seen the most robust infants suffer at the time of eruption of each group of teeth, and has also observed puny and

feeble subjects pass through the process with little or no trouble.

The third and fourth groups of teeth are most prone to make trouble, and when the child is born at such a time of the year as to bring the eruption of these during the hot months, illness of some sort may be anticipated. This is often dangerous and sometimes fatal; hence the popular dread of the "second summer."

The order of eruption of the permanent teeth is as follows:

The two central incisors of lower jaw, from the 6th to 8th year.

7th to 8th "
8th to 9th

9th to 10th

66

66

66

These replace the temporary teeth; those which are developed de novo appear thus :

The four first molars, from the 5th to 7th year.

second molars, from the 12th to 13th year.
third molars, from the 17th to 21st year.

There are, therefore, twelve more permanent teeth, making thirty-two in all-sixteen in each jaw.

The diagram, Fig. 6, will aid in explaining the

DIAGRAM SHOWING RELATION BETWEEN PERMANENT AND TEMPORARY TEETH.

The figures 1, 2, 3, etc., indicate the groups of teeth and the order of their appearance.

Second dentition is a common cause of ill health in late childhood. The disorders produced by this process, however, are not so well defined nor so dangerous as those of primary dentition, and, in consequence, the relation of cause and effect is often overlooked.

It is probable that the first and seventh sets are the most apt to give rise to both local and constitutional disturbances.

CHAPTER II.

THE NURSERY.

Every well-regulated house in which there are children should be provided with two nurseries, one for occupation by day, the other by night.

Before entering further into the subject, however, attention must be directed to the fact that the American city-bred child, belonging to the class in which it is possible to provide separate rooms for nurseries, is to a greater or less degree a migratory creature. For when the first warm days of May or early June make the parents bask at open windows, the child is hurried off to a suburban hotel or farmhouse or to the sea-coast. Again, so soon as the cold evenings of late September suggest the comfort of an open fire, equal energy is exhibited to get him back to cosy winter quarters. In summer, most of the waking hours are spent in the open air, in winter, the greater proportion indoors, hence the day nursery must be regarded as a winter resort, and as such must possess qualities that would render it uninhabitable by the child in hot weather. The night nursery should have, though to a much less degree, the same qualities. In