The age at which the child begins to cut teeth varies greatly in the different individuals with no apparent reason. There are twenty deciduous or milk teeth and they make their appearance in the following order and at an average time as shown in the data. From six to eight months of age the lower central incisors appear. The four upper incisors do not appear until from the seventh to the tenth month; then the two lower lateral incisors and four anterior molars come through between the tenth and fourteenth month. From a year and a half to two years of age the four canines put in their appearance, and from two years to two and a half the four posterior molars. This completes the set. By the time a child is one year of age he should have six teeth; at the age of one and a half years, twelve teeth; at two years, sixteen teeth; and by the time he is two and a half years of age he should have the entire set of twenty. The table below gives the order in which the deciduous teeth appear and the approximate time when they may be expected. This time is subject to great variation. This variation does not necessarily indicate an abnormality. In some children the teeth appear much earlier than in others. The appearance of the first teeth may be as late as the tenth month in perfectly healthy children. However, if the delay is too great attention should be given the child. 6 to 8 months of age the two lower central incisors. 7 to 10 ” ” ” the four upper incisors. 10 to 14 ” ” ” two lateral incisors, four anterior molars. 16 to 24 ” ” ” four canines. 22 to 30 ” ” ” the four posterior molars. Normal children cut their teeth without any very severe symptoms. If the child is below normal, or if there are meric zones in which the structures are not receiving a sufficient amount of mental impulses, symptoms will be produced. At the time of dentition many incoördinations may appear, not because the process of cutting the teeth produces these conditions, but because the process requires a great expenditure of internal energy to produce the eruption of the teeth, hence at such times the forces of the body are very heavily drawn upon. The force that might be used in bringing about adaptation to other conditions must be used in this process. If the child is normal the growth of the teeth will produce no more symptoms than the growth of the nails. During the time teeth are coming through the gums there may be increased salivation and drooling and a tendency for the child to chew on the fingers. Irritability and restlessness at night are very frequent symptoms. It is quite common to have gastro-intestinal disturbances and especially diarrhea.