e retention and excretion of salts, and especially of
calcium, a circumstance which becomes of significance when we remember
how frequently rickety changes, tetany, and other convulsive seizures
form part of the clinical picture which we are now considering. While
it is difficult to determine the effect of repeated infections upon
the functions of the endocrine glands, we have clear evidence of the
deleterious influence upon almost all the tissues of the body, the
functioning of which it is more easy to estimate. For example, the
cells of the skin and of the mucous membranes which happen to be
visible to the eye show clear evidence of diminished vitality and
increased vulnerability. Physiological stimuli, incapable of producing
any visible reaction in healthy children, habitually determine widely
spread and persistent inflammatory reactions. For example, the
licking movements of the tongue at the corners of the mouth produce
the little unhealthy fissures which the French call _perleche_. The
physiological stimulus of the erupting tooth is capable of causing a
painful irritation of the gum, so that the child is said to suffer
from teething, accompanied, it may be, and the association is
significant, by "teething convulsions." The irritation of the urine
produces rawness and excoriation of the skin of the prepuce, contact
with intestinal contents not in themselves very abnormal, an
intractable dermatitis of the buttocks or a persistent diarrhoea and
enteral catarrh. Improvement in the general health, the result of the
cessation for the time being of the recurrent infections, perhaps
consequent upon improved hygienic conditions, always determines the
rapid disappearance of all these accompaniments of the general
diminution of tissue vitality.

The muscular system and the bones are commonly also involved, so that
rickety changes are often found in these infantile and watery
children. In early childhood the processes of calcification and
decalcification proceed side by side and with great rapidity, and in
health there is always a balance on the side of the constructive
process. In the children whom we are now considering, saturated as
they are, from time to time, with the toxins resulting from repeated
infection, ossification may be so interfered with as to cause
softening and bending, with the evolution of a state of rickets.
Between bone and muscle, too, we find a close relationship. We do not
find powerful muscles with s