ation, or the length of time between
exposure to the disease and the development of the symptoms, is between
two and five days. In its mild form the disease may be present without
giving any constitutional symptoms. In its severe form, however, it is
one of the most dangerous diseases of childhood. In large cities it is
present all the year round with more or less frequent outbreaks in the
form of local epidemics. In the country it is only seen in its epidemic
form. It does not arise without a cause, that is, there is always a
preceding case from which an epidemic springs, though it is not always
easy to trace the connection. The child inhales the bacilli which cause
the disease with the air it breathes. The bacilli may lodge on toys or
other articles from which the child gets them. Direct infection is
usually the mode of communication through which a child obtains the
disease. The saliva and mucus from the nose contain the bacilli in large
quantities and if a patient coughs or sneezes they are expelled in this
way and infect others. Frequently a child suffering from a mild form of
diphtheria may attend school and infect others without it being known
that the child has the disease.

Symptoms.--The symptoms vary with the severity of the attack. There
are mild cases, as has been stated, that give no constitutional
symptoms. There may be a small amount of local disturbance in the throat
or nose and there may be some membrane present, but, for some reason,
there does not seem to be any absorption of the poison into the system
and the child escapes the systemic disturbance. Even as a local
condition these cases vary. There is always a fever at the beginning,
but the child never seems sick enough to go to bed. If the throat is
examined it will be found to be red and slightly inflamed, there may be
spots on the tonsils, or there may be a gray film over them. There is no
discharge from the nose and the child does not complain of an excess of
mucus from the throat. The spots may last for a week and then disappear.
These cases are difficult to diagnose without making a culture, and if
the physician insists upon keeping the child confined to bed while
apparently well the family as a rule object, though it is absolutely
necessary. These are the cases that do great harm in school, and no
mother should object if the physician insists in taking preventative
measures to stop an epidemic if the bacilli have been found in the
child's thr