and was replaced by some sort of fatty tissue.  Nowadays, it is held that secretion cells persist throughout life.  When the extent of this persistence is too great, the gland being from five to ten times as large as the normal, a number of other features become prominent to make the extraordinary individual, the status lymphaticus, who amid the hazards of life will react in an extraordinary way.  He will be taken up in the consideration of internal secretion personalities.

Then there are the varied and remarkable phenomena of thymus enlargement and hyperactivity in childhood itself.  When an enlarged thymus is present in an infant, the initiation of breathing in the new-born, the introduction of the newcomer to the oxygen of the air, may be an exceedingly prolonged, difficult, matter.  Such a baby is said to be born blue, and the breathing may be stridorous for days, becoming normal for a time, to be followed later by spells of trouble in breathing, breathlessness or breathlessness with blueness, and threatened extinction.  Sometimes these spells come out of a clear sky in an apparently healthy child.  That some poison, probably an oversecretion of the thymus, is responsible is shown by the relief obtainable by X-ray shrinkage of the gland, or the surgical removal of a part of it.

Moreover, the gland is influenced by and influences the factors of body weight and growth with an extreme readiness and lability.  Deficient general undernutrition leads to rapid decline in its weight.  Back in 1858, the pioneer student of the thymus, Friedleben, declared that the size and condition of the thymus is an index to be the state of nutrition of the body.  Underfeeding for four weeks will reduce it to one thirtieth the normal.  It seems to act as a storage and reserve organ, affording some protection against the limitation of growth by lack of food material.  In exhausting or wasting disease, the weight of the gland sinks much more quickly than other glands.  Scattered instances have been reported of children growing, putting on inches in height and expanding mentally, when thymus was fed to them, in whom every other measure previously tried had failed.  A French study of over four hundred idiotic children with normal thyroids reported that over three fourths had no thymus at all.  Everything points to the most direct and close relation between the gland and nutrition and growth, but with nothing tangibly definite like our knowledge of the thyroid and the pituitary.

There is evidence that the thymus is involved in the health and efficiency of muscle cells and muscularity.  Certain tumors of the thymus, presumably destructive of the gland substance proper, and thus cutting off its secretion, are accompanied by a singular muscle weakness and atrophy of the muscle cells, entirely out of proportion to the general damage suffered by the other cells of the body when affected by the poison of a malignant growth.  Also, the thymus has been discovered diseased in certain mysterious progressive muscular wastings.  A remarkable fatigability of muscles, which appears after the slightest exertion, is a feature.  The feeding of thymus has caused muscle cramps which apparently depends upon an increased excitability of the muscle nerve endings.